CVE-2026-99279

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99279", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.405Z", "datePublished": "2026-11-07T14:08:47.243Z", "dateUpdated": "2026-11-07T14:08:47.243Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-11-07T14:08:47.243Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: reclaim ended sessions on logoff and expiration\n\nLOGOFF and previous-session replacement leave sessions Expired with a\nzero credential expiry. Ended sessions can retain their memory and\nconnection slots when no further setup arrives on the owning connection.\n\nUnpublish a logged-off session while the request reference keeps its\nresponse signing and encryption keys alive. Remove its procfs entry\nbefore dropping the table reference so a reader cannot remove its own\nentry on the last put. Clear proc_entry after removal to avoid removing\nit twice.\n\nReclaim ended sessions from the global table in the existing expiration\nworker before it acquires conn_list_lock. Only select Expired sessions\nwith zero credential expiry and no references beyond the table\nreference. Keep sessions whose Kerberos credentials expired available\nfor reauthentication.\n\nUnlink the session from its setup connection and all channel\nconnections, so SMB2 sessions and sessions with only secondary SMB3\nchannels are covered. The session already holds connection references,\nand sessions_table_lock prevents concurrent channel removal. Queue\nsessions on a separate disposal list, leaving their hash nodes unhashed,\nand remove procfs entries and drop table references outside the locks.\n\nKeep the pending setup check before allocating a new session so\nabandoned InProgress sessions can release their slots even at the\nconnection limit. Retain the timeout and reference checks and dispose of\nthose sessions outside the locks. Leave ended Expired sessions to the\nexpiration worker."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/connection.c", "fs/smb/server/mgmt/user_session.c", "fs/smb/server/mgmt/user_session.h", "fs/smb/server/smb2pdu.c"], "versions": [{"version": "d7fd1f98607f2cd358e583f9548bdf0173090a86", "lessThan": "1767a5e45dbf6a3b12105196dda4fb0ef80b9698", "status": "affected", "versionType": "git"}, {"version": "d7fd1f98607f2cd358e583f9548bdf0173090a86", "lessThan": "26534ef335e92b028eb58e44d98d46a0e26af0ec", "status": "affected", "versionType": "git"}, {"version": "c99ea7855124ca1428a1e59c2b4590aaef34eacf", "status": "affected", "versionType": "git"}, {"version": "7.2.8", "lessThan": "7.3", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/connection.c", "fs/smb/server/mgmt/user_session.c", "fs/smb/server/mgmt/user_session.h", "fs/smb/server/smb2pdu.c"], "versions": [{"version": "7.3", "status": "affected"}, {"version": "0", "lessThan": "7.3", "status": "unaffected", "versionType": "semver"}, {"version": "7.3.2", "lessThanOrEqual": "7.3.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.4-rc1", "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": "7.3", "versionEndExcluding": "7.3.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.3", "versionEndExcluding": "7.4-rc1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.2.8"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1767a5e45dbf6a3b12105196dda4fb0ef80b9698"}, {"url": "https://git.kernel.org/stable/c/26534ef335e92b028eb58e44d98d46a0e26af0ec"}], "title": "ksmbd: reclaim ended sessions on logoff and expiration", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/server/connection.c", "fs/smb/server/mgmt/user_session.c", "fs/smb/server/mgmt/user_session.h", "fs/smb/server/smb2pdu.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "1767a5e45dbf6a3b12105196dda4fb0ef80b9698", "status": "affected", "version": "d7fd1f98607f2cd358e583f9548bdf0173090a86", "versionType": "git"}, {"lessThan": "26534ef335e92b028eb58e44d98d46a0e26af0ec", "status": "affected", "version": "d7fd1f98607f2cd358e583f9548bdf0173090a86", "versionType": "git"}, {"status": "affected", "version": "c99ea7855124ca1428a1e59c2b4590aaef34eacf", "versionType": "git"}, {"lessThan": "7.3", "status": "affected", "version": "7.2.8", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/server/connection.c", "fs/smb/server/mgmt/user_session.c", "fs/smb/server/mgmt/user_session.h", "fs/smb/server/smb2pdu.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.3"}, {"lessThan": "7.3", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.3.*", "status": "unaffected", "version": "7.3.2", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.4-rc1", "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\nksmbd: reclaim ended sessions on logoff and expiration\n\nLOGOFF and previous-session replacement leave sessions Expired with a\nzero credential expiry. Ended sessions can retain their memory and\nconnection slots when no further setup arrives on the owning connection.\n\nUnpublish a logged-off session while the request reference keeps its\nresponse signing and encryption keys alive. Remove its procfs entry\nbefore dropping the table reference so a reader cannot remove its own\nentry on the last put. Clear proc_entry after removal to avoid removing\nit twice.\n\nReclaim ended sessions from the global table in the existing expiration\nworker before it acquires conn_list_lock. Only select Expired sessions\nwith zero credential expiry and no references beyond the table\nreference. Keep sessions whose Kerberos credentials expired available\nfor reauthentication.\n\nUnlink the session from its setup connection and all channel\nconnections, so SMB2 sessions and sessions with only secondary SMB3\nchannels are covered. The session already holds connection references,\nand sessions_table_lock prevents concurrent channel removal. Queue\nsessions on a separate disposal list, leaving their hash nodes unhashed,\nand remove procfs entries and drop table references outside the locks.\n\nKeep the pending setup check before allocating a new session so\nabandoned InProgress sessions can release their slots even at the\nconnection limit. Retain the timeout and reference checks and dispose of\nthose sessions outside the locks. Leave ended Expired sessions to the\nexpiration worker."}], "id": "CVE-2026-99279", "lastModified": "2026-11-07T14:17:03.317", "metrics": {}, "published": "2026-11-07T14:17:03.317", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1767a5e45dbf6a3b12105196dda4fb0ef80b9698"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/26534ef335e92b028eb58e44d98d46a0e26af0ec"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: kernel: ksmbd: Denial of Service via unreclaimed expired sessions", "id": "2568625", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2568625"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-772", "details": ["A flaw was found in the Linux kernel's ksmbd (Server Message Block) server. Expired sessions resulting from logoff or session replacement are not properly reclaimed when no further setup requests arrive on the connection. A remote attacker can exploit this flaw to retain allocated memory and connection slots, leading to resource exhaustion and a Denial of Service (DoS)."], "mitigation": {"lang": "en:us", "value": "To mitigate this vulnerability, prevent the ksmbd kernel module from being loaded by adding a configuration file to /etc/modprobe.d:\n# echo \"install ksmbd /bin/false\" > /etc/modprobe.d/ksmbd.conf\nIf the module is currently loaded in memory, unload it:\n# modprobe -r ksmbd\nIf ksmbd is required for operations and cannot be disabled, restrict incoming network traffic to the SMB port (default TCP port 445) to trusted clients only using firewall rules.\nWarning: Unloading the kernel module will immediately terminate all active SMB sessions and disrupt file-sharing services for connected clients. Reloading firewall rules or restarting network services may cause temporary connection interruptions."}, "name": "CVE-2026-99279", "package_state": [{"cpe": "cpe:/a:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:rhel_els:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:rhel_els:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:rhel_els:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/a:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/a:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/a:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:5", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-10", "product_name": "Red Hat OpenShift Container Platform 5"}, {"cpe": "cpe:/a:redhat:openshift:5", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 5"}], "public_date": "2026-11-07T14:08:47Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-99279\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-99279\nhttps://git.kernel.org/stable/c/1767a5e45dbf6a3b12105196dda4fb0ef80b9698\nhttps://git.kernel.org/stable/c/26534ef335e92b028eb58e44d98d46a0e26af0ec"], "statement": "This vulnerability is rated as Moderate severity because exploitation requires an authenticated remote user to establish sessions, and the impact is confined to a denial of service caused by memory and connection exhaustion rather than code execution or data compromise. In standard Red Hat Enterprise Linux environments, the in-kernel SMB server (ksmbd) is not loaded or configured by default, as user-space Samba serves as the standard SMB implementation. Systems are only exposed to risk if the ksmbd kernel module has been explicitly enabled and made accessible over the network.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7fd1f98607f2cd358e583f9548bdf0173090a86,1767a5e45dbf6a3b12105196dda4fb0ef80b9698)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7fd1f98607f2cd358e583f9548bdf0173090a86,26534ef335e92b028eb58e44d98d46a0e26af0ec)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "c99ea7855124ca1428a1e59c2b4590aaef34eacf"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[7.2.8,7.3)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "7.3"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,7.3)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3.2,7.4.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.4-rc1,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7fd1f98607f2cd358e583f9548bdf0173090a86,1767a5e45dbf6a3b12105196dda4fb0ef80b9698)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7fd1f98607f2cd358e583f9548bdf0173090a86,26534ef335e92b028eb58e44d98d46a0e26af0ec)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "c99ea7855124ca1428a1e59c2b4590aaef34eacf"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[7.2.8,7.3)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"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": "7.3"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,7.3)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3.2,7.4.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.4-rc1,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-11-07T15:30:07.507251+00:00", "updated": "2026-11-08T01:30:18.806465+00:00", "vendors": ["linux", "linux$PRODUCT$linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-401", "CWE-770", "CWE-772"]}