CVE-2026-74740

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74740", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.930Z", "datePublished": "2026-08-26T14:36:52.344Z", "dateUpdated": "2026-10-30T12:30:29.380Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:30:29.380Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_api: fix TOCTOU NULL deref on a->goto_chain\n\ntcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking\nrcu_access_pointer(a->goto_chain) and then calling\ntcf_action_goto_chain_exec(), which does a second, independent\nrcu_dereference_bh(a->goto_chain) read and immediately dereferences\nchain->filter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact\nreplace path) can clear a->goto_chain between the two reads, so the second\nread returns NULL and tcf_action_goto_chain_exec() dereferences NULL.\n\nFix the race by doing a single rcu_dereference_bh() read of a->goto_chain\nin tcf_action_exec(), checking it once for NULL, and passing the resulting\nchain pointer into tcf_action_goto_chain_exec(). This turns the split\ncheck/use into a single check/use on one value."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/act_api.c"], "versions": [{"version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "lessThan": "28aa0c9dd0b1b38436995d4c15621ad3f896c7e3", "status": "affected", "versionType": "git"}, {"version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "lessThan": "91d55fd1fdb85c8371ca8793c788ea7d5192383a", "status": "affected", "versionType": "git"}, {"version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "lessThan": "1ec48b6715c29b20105e3485206602cff6c51ae5", "status": "affected", "versionType": "git"}, {"version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "lessThan": "abceabc4408fca6a9dd52611f5d197dec9390d63", "status": "affected", "versionType": "git"}, {"version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "lessThan": "6b70886ebc428eed43a069c8944a931b5fb3f4e4", "status": "affected", "versionType": "git"}, {"version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "lessThan": "f60b396ee174206fe08ebf997d16cd3801b77b22", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/act_api.c"], "versions": [{"version": "5.1", "status": "affected"}, {"version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.153", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.105", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.46", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.10", "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": "5.1", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.153"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.105"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.46"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.1.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/28aa0c9dd0b1b38436995d4c15621ad3f896c7e3"}, {"url": "https://git.kernel.org/stable/c/91d55fd1fdb85c8371ca8793c788ea7d5192383a"}, {"url": "https://git.kernel.org/stable/c/1ec48b6715c29b20105e3485206602cff6c51ae5"}, {"url": "https://git.kernel.org/stable/c/abceabc4408fca6a9dd52611f5d197dec9390d63"}, {"url": "https://git.kernel.org/stable/c/6b70886ebc428eed43a069c8944a931b5fb3f4e4"}, {"url": "https://git.kernel.org/stable/c/f60b396ee174206fe08ebf997d16cd3801b77b22"}], "title": "net/sched: act_api: fix TOCTOU NULL deref on a->goto_chain", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sched/act_api.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "28aa0c9dd0b1b38436995d4c15621ad3f896c7e3", "status": "affected", "version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "versionType": "git"}, {"lessThan": "91d55fd1fdb85c8371ca8793c788ea7d5192383a", "status": "affected", "version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "versionType": "git"}, {"lessThan": "1ec48b6715c29b20105e3485206602cff6c51ae5", "status": "affected", "version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "versionType": "git"}, {"lessThan": "abceabc4408fca6a9dd52611f5d197dec9390d63", "status": "affected", "version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "versionType": "git"}, {"lessThan": "6b70886ebc428eed43a069c8944a931b5fb3f4e4", "status": "affected", "version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "versionType": "git"}, {"lessThan": "f60b396ee174206fe08ebf997d16cd3801b77b22", "status": "affected", "version": "ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sched/act_api.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.1"}, {"lessThan": "5.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.153", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.105", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.46", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.10", "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\nnet/sched: act_api: fix TOCTOU NULL deref on a->goto_chain\n\ntcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking\nrcu_access_pointer(a->goto_chain) and then calling\ntcf_action_goto_chain_exec(), which does a second, independent\nrcu_dereference_bh(a->goto_chain) read and immediately dereferences\nchain->filter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact\nreplace path) can clear a->goto_chain between the two reads, so the second\nread returns NULL and tcf_action_goto_chain_exec() dereferences NULL.\n\nFix the race by doing a single rcu_dereference_bh() read of a->goto_chain\nin tcf_action_exec(), checking it once for NULL, and passing the resulting\nchain pointer into tcf_action_goto_chain_exec(). This turns the split\ncheck/use into a single check/use on one value."}], "id": "CVE-2026-74740", "lastModified": "2026-10-30T13:20:05.597", "metrics": {}, "published": "2026-08-26T15:16:52.743", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1ec48b6715c29b20105e3485206602cff6c51ae5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/28aa0c9dd0b1b38436995d4c15621ad3f896c7e3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6b70886ebc428eed43a069c8944a931b5fb3f4e4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/91d55fd1fdb85c8371ca8793c788ea7d5192383a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/abceabc4408fca6a9dd52611f5d197dec9390d63"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f60b396ee174206fe08ebf997d16cd3801b77b22"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net/sched: act_api: fix TOCTOU NULL deref on a->goto_chain", "id": "2524470", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2524470"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/sched: act_api: fix TOCTOU NULL deref on a->goto_chain\ntcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking\nrcu_access_pointer(a->goto_chain) and then calling\ntcf_action_goto_chain_exec(), which does a second, independent\nrcu_dereference_bh(a->goto_chain) read and immediately dereferences\nchain->filter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact\nreplace path) can clear a->goto_chain between the two reads, so the second\nread returns NULL and tcf_action_goto_chain_exec() dereferences NULL.\nFix the race by doing a single rcu_dereference_bh() read of a->goto_chain\nin tcf_action_exec(), checking it once for NULL, and passing the resulting\nchain pointer into tcf_action_goto_chain_exec(). This turns the split\ncheck/use into a single check/use on one value.", "A flaw was found in the Linux kernel's network scheduler (net/sched: act_api). A Time-of-Check to Time-of-Use (TOCTOU) race condition exists where a pointer can be cleared between two reads. This allows a concurrent operation to cause a NULL dereference, potentially leading to a system crash and Denial of Service (DoS)."], "name": "CVE-2026-74740", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-26T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74740\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74740\nhttps://lore.kernel.org/linux-cve-announce/2026082657-CVE-2026-74740-dae7@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5,91d55fd1fdb85c8371ca8793c788ea7d5192383a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5,1ec48b6715c29b20105e3485206602cff6c51ae5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5,abceabc4408fca6a9dd52611f5d197dec9390d63)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5,6b70886ebc428eed43a069c8944a931b5fb3f4e4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ee3bbfe806cdb46b02cda63626cb50a7a7b19fc5,f60b396ee174206fe08ebf997d16cd3801b77b22)"}}], "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": "generic", "value": "5.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.153,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.105,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.46,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.10,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "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": "2026-08-26T15:30:05.170674+00:00", "updated": "2026-08-28T18:30:08.317953+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}