CVE-2026-74556

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74556", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.916Z", "datePublished": "2026-08-15T12:28:01.359Z", "dateUpdated": "2026-10-16T19:05:55.568Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:38:57.393Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer\n\niscsi_tcp_hdr_dissect() receives the data segment of several PDU types\ninto the fixed-size conn->data buffer, which is allocated for\nISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP,\nREJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU\nwhose DataSegmentLength exceeds that buffer.\n\nThe SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its\ndata segment (sense/response data) into conn->data via\niscsi_tcp_data_recv_prep(), but it does so without the same check. The\nonly upstream bound on in.datalen is conn->max_recv_dlength, the\ninitiator's advertised MaxRecvDataSegmentLength, which is commonly\nnegotiated well above 8192 (open-iscsi defaults to 262144). A target\nthat returns a SCSI Response with a DataSegmentLength between 8193 and\nmax_recv_dlength therefore overflows the 8192-byte conn->data buffer.\n\nOnce the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly\nlike those responses: bound the data segment, receive it into conn->data\nwhen present, and otherwise complete the PDU with no data. Fold the\nopcode into that case group rather than duplicating the check."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - A malicious or compromised iSCSI target delivers crafted SCSI Command Response PDUs over the established TCP iSCSI session; reception flows through iscsi_sw_tcp_recv/iscsi_tcp_recv_skb into iscsi_tcp_hdr_dissect without local access.\nAC:L - The attacker controls the target and can set DataSegmentLength between 8193 and negotiated max_recv_dlength (open-iscsi commonly 262144) on SCSI_CMD_RSP for any outstanding command ITT; no races or victim-specific heap layout are required.\nPR:N - No privileges on the victim host are needed; a remote attacker acting as or MITMing the iSCSI target sends malicious responses after session login, independent of victim user accounts or capabilities.\nUI:N - On systems with persistent iSCSI sessions (cloud VMs, SAN-boot hosts, Kubernetes iSCSI volumes), exploitation triggers automatically during normal SCSI I/O when command responses are received; no victim action is needed at attack time.\nS:U - Heap corruption is confined to the kernel iSCSI initiator on the affected host; successful exploitation yields kernel compromise or DoS within the same security authority, not a VM escape or cross-boundary scope change.\nC:H - iscsi_tcp_segment_recv memcpy writes up to max_recv_dlength bytes into an 8192-byte conn->data buffer, causing a large heap overflow whose controlled corruption can be leveraged for arbitrary kernel memory disclosure.\nI:H - Attacker-controlled response data is copied past the fixed conn->data allocation via iscsi_tcp_data_recv_prep/iscsi_segment_init_linear, enabling heap metadata/object corruption exploitable for arbitrary kernel write and privilege escalation.\nA:H - Overflowing the conn->data heap buffer can immediately corrupt adjacent kernel allocations and cause oops/panic; a malicious target can repeatedly trigger this on active sessions to deny storage availability."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/scsi/libiscsi_tcp.c"], "versions": [{"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "a51812842084fd390590ab8dc0431f10c73ddc56", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "a8f94cc9f0e5759252551be3a172960c57f21f54", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "f1a3a51fc5dba0e99532379665069f1700da6b44", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "c97b5265cc47775f77fd2a23d6bde0426997b233", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "084af0253673425ce2ae62e3c7f74f0dd023711b", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "72815741715bd41556dac5eeb068bf0f8af06ee7", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676", "status": "affected", "versionType": "git"}, {"version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "c1dea15f819cded9b3faf58f8bec72323568b6e6", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/scsi/libiscsi_tcp.c"], "versions": [{"version": "2.6.29", "status": "affected"}, {"version": "0", "lessThan": "2.6.29", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.6.151"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.12.103"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.18.44"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "7.1.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/a51812842084fd390590ab8dc0431f10c73ddc56"}, {"url": "https://git.kernel.org/stable/c/a8f94cc9f0e5759252551be3a172960c57f21f54"}, {"url": "https://git.kernel.org/stable/c/f1a3a51fc5dba0e99532379665069f1700da6b44"}, {"url": "https://git.kernel.org/stable/c/c97b5265cc47775f77fd2a23d6bde0426997b233"}, {"url": "https://git.kernel.org/stable/c/084af0253673425ce2ae62e3c7f74f0dd023711b"}, {"url": "https://git.kernel.org/stable/c/72815741715bd41556dac5eeb068bf0f8af06ee7"}, {"url": "https://git.kernel.org/stable/c/b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676"}, {"url": "https://git.kernel.org/stable/c/c1dea15f819cded9b3faf58f8bec72323568b6e6"}], "title": "scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74556", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:00:06.190671Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:55.568Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74556", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:00:06.190671Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:00:07.359Z"}}], "cna": {"title": "scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 9.8, "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - A malicious or compromised iSCSI target delivers crafted SCSI Command Response PDUs over the established TCP iSCSI session; reception flows through iscsi_sw_tcp_recv/iscsi_tcp_recv_skb into iscsi_tcp_hdr_dissect without local access.\nAC:L - The attacker controls the target and can set DataSegmentLength between 8193 and negotiated max_recv_dlength (open-iscsi commonly 262144) on SCSI_CMD_RSP for any outstanding command ITT; no races or victim-specific heap layout are required.\nPR:N - No privileges on the victim host are needed; a remote attacker acting as or MITMing the iSCSI target sends malicious responses after session login, independent of victim user accounts or capabilities.\nUI:N - On systems with persistent iSCSI sessions (cloud VMs, SAN-boot hosts, Kubernetes iSCSI volumes), exploitation triggers automatically during normal SCSI I/O when command responses are received; no victim action is needed at attack time.\nS:U - Heap corruption is confined to the kernel iSCSI initiator on the affected host; successful exploitation yields kernel compromise or DoS within the same security authority, not a VM escape or cross-boundary scope change.\nC:H - iscsi_tcp_segment_recv memcpy writes up to max_recv_dlength bytes into an 8192-byte conn->data buffer, causing a large heap overflow whose controlled corruption can be leveraged for arbitrary kernel memory disclosure.\nI:H - Attacker-controlled response data is copied past the fixed conn->data allocation via iscsi_tcp_data_recv_prep/iscsi_segment_init_linear, enabling heap metadata/object corruption exploitable for arbitrary kernel write and privilege escalation.\nA:H - Overflowing the conn->data heap buffer can immediately corrupt adjacent kernel allocations and cause oops/panic; a malicious target can repeatedly trigger this on active sessions to deny storage availability."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "a51812842084fd390590ab8dc0431f10c73ddc56", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "a8f94cc9f0e5759252551be3a172960c57f21f54", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "f1a3a51fc5dba0e99532379665069f1700da6b44", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "c97b5265cc47775f77fd2a23d6bde0426997b233", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "084af0253673425ce2ae62e3c7f74f0dd023711b", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "72815741715bd41556dac5eeb068bf0f8af06ee7", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676", "versionType": "git"}, {"status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "lessThan": "c1dea15f819cded9b3faf58f8bec72323568b6e6", "versionType": "git"}], "programFiles": ["drivers/scsi/libiscsi_tcp.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "2.6.29"}, {"status": "unaffected", "version": "0", "lessThan": "2.6.29", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.265", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.216", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.183", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.151", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.103", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.44", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.8", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/scsi/libiscsi_tcp.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/a51812842084fd390590ab8dc0431f10c73ddc56"}, {"url": "https://git.kernel.org/stable/c/a8f94cc9f0e5759252551be3a172960c57f21f54"}, {"url": "https://git.kernel.org/stable/c/f1a3a51fc5dba0e99532379665069f1700da6b44"}, {"url": "https://git.kernel.org/stable/c/c97b5265cc47775f77fd2a23d6bde0426997b233"}, {"url": "https://git.kernel.org/stable/c/084af0253673425ce2ae62e3c7f74f0dd023711b"}, {"url": "https://git.kernel.org/stable/c/72815741715bd41556dac5eeb068bf0f8af06ee7"}, {"url": "https://git.kernel.org/stable/c/b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676"}, {"url": "https://git.kernel.org/stable/c/c1dea15f819cded9b3faf58f8bec72323568b6e6"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer\n\niscsi_tcp_hdr_dissect() receives the data segment of several PDU types\ninto the fixed-size conn->data buffer, which is allocated for\nISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP,\nREJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU\nwhose DataSegmentLength exceeds that buffer.\n\nThe SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its\ndata segment (sense/response data) into conn->data via\niscsi_tcp_data_recv_prep(), but it does so without the same check. The\nonly upstream bound on in.datalen is conn->max_recv_dlength, the\ninitiator's advertised MaxRecvDataSegmentLength, which is commonly\nnegotiated well above 8192 (open-iscsi defaults to 262144). A target\nthat returns a SCSI Response with a DataSegmentLength between 8193 and\nmax_recv_dlength therefore overflows the 8192-byte conn->data buffer.\n\nOnce the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly\nlike those responses: bound the data segment, receive it into conn->data\nwhen present, and otherwise complete the PDU with no data. Fold the\nopcode into that case group rather than duplicating the check."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.265", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.216", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.183", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.151", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.103", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.44", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.8", "versionStartIncluding": "2.6.29"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "2.6.29"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:38:57.393Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74556", "state": "PUBLISHED", "dateUpdated": "2026-10-16T19:05:55.568Z", "dateReserved": "2026-08-15T05:44:03.916Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-15T12:28:01.359Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/scsi/libiscsi_tcp.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "a51812842084fd390590ab8dc0431f10c73ddc56", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "a8f94cc9f0e5759252551be3a172960c57f21f54", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "f1a3a51fc5dba0e99532379665069f1700da6b44", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "c97b5265cc47775f77fd2a23d6bde0426997b233", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "084af0253673425ce2ae62e3c7f74f0dd023711b", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "72815741715bd41556dac5eeb068bf0f8af06ee7", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}, {"lessThan": "c1dea15f819cded9b3faf58f8bec72323568b6e6", "status": "affected", "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/scsi/libiscsi_tcp.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.29"}, {"lessThan": "2.6.29", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.183", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.151", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.103", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.44", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.8", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer\n\niscsi_tcp_hdr_dissect() receives the data segment of several PDU types\ninto the fixed-size conn->data buffer, which is allocated for\nISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP,\nREJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU\nwhose DataSegmentLength exceeds that buffer.\n\nThe SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its\ndata segment (sense/response data) into conn->data via\niscsi_tcp_data_recv_prep(), but it does so without the same check. The\nonly upstream bound on in.datalen is conn->max_recv_dlength, the\ninitiator's advertised MaxRecvDataSegmentLength, which is commonly\nnegotiated well above 8192 (open-iscsi defaults to 262144). A target\nthat returns a SCSI Response with a DataSegmentLength between 8193 and\nmax_recv_dlength therefore overflows the 8192-byte conn->data buffer.\n\nOnce the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly\nlike those responses: bound the data segment, receive it into conn->data\nwhen present, and otherwise complete the PDU with no data. Fold the\nopcode into that case group rather than duplicating the check."}], "id": "CVE-2026-74556", "lastModified": "2026-10-16T20:17:37.307", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74556", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:00:06.190671Z", "version": "2.0.3"}}]}, "published": "2026-08-15T13:18:01.047", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/084af0253673425ce2ae62e3c7f74f0dd023711b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/72815741715bd41556dac5eeb068bf0f8af06ee7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a51812842084fd390590ab8dc0431f10c73ddc56"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a8f94cc9f0e5759252551be3a172960c57f21f54"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c1dea15f819cded9b3faf58f8bec72323568b6e6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c97b5265cc47775f77fd2a23d6bde0426997b233"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f1a3a51fc5dba0e99532379665069f1700da6b44"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer", "id": "2517010", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517010"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-120", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nscsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer\niscsi_tcp_hdr_dissect() receives the data segment of several PDU types\ninto the fixed-size conn->data buffer, which is allocated for\nISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP,\nREJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU\nwhose DataSegmentLength exceeds that buffer.\nThe SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its\ndata segment (sense/response data) into conn->data via\niscsi_tcp_data_recv_prep(), but it does so without the same check. The\nonly upstream bound on in.datalen is conn->max_recv_dlength, the\ninitiator's advertised MaxRecvDataSegmentLength, which is commonly\nnegotiated well above 8192 (open-iscsi defaults to 262144). A target\nthat returns a SCSI Response with a DataSegmentLength between 8193 and\nmax_recv_dlength therefore overflows the 8192-byte conn->data buffer.\nOnce the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly\nlike those responses: bound the data segment, receive it into conn->data\nwhen present, and otherwise complete the PDU with no data. Fold the\nopcode into that case group rather than duplicating the check.", "A flaw was found in the Linux kernel's `libiscsi_tcp` component. A remote attacker, acting as a malicious iSCSI target, could send a specially crafted iSCSI SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) with an oversized data segment. This could lead to a buffer overflow in a fixed-size buffer, potentially causing memory corruption within the kernel."], "name": "CVE-2026-74556", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74556\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74556\nhttps://lore.kernel.org/linux-cve-announce/2026081551-CVE-2026-74556-3eb4@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a081c13e39b5c17052a7b46fafa61019c4c110ff,c97b5265cc47775f77fd2a23d6bde0426997b233)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a081c13e39b5c17052a7b46fafa61019c4c110ff,084af0253673425ce2ae62e3c7f74f0dd023711b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a081c13e39b5c17052a7b46fafa61019c4c110ff,72815741715bd41556dac5eeb068bf0f8af06ee7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a081c13e39b5c17052a7b46fafa61019c4c110ff,b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[a081c13e39b5c17052a7b46fafa61019c4c110ff,c1dea15f819cded9b3faf58f8bec72323568b6e6)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "2.6.29"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,2.6.29)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.151,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.103,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.44,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.8,8.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc6,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T15:30:09.535281+00:00", "updated": "2026-08-22T02:15:03.746368+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}