{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23270", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.991Z", "datePublished": "2026-03-18T17:54:43.803Z", "dateUpdated": "2026-03-18T17:54:43.803Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-03-18T17:54:43.803Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks\n\nAs Paolo said earlier [1]:\n\n\"Since the blamed commit below, classify can return TC_ACT_CONSUMED while\nthe current skb being held by the defragmentation engine. As reported by\nGangMin Kim, if such packet is that may cause a UaF when the defrag engine\nlater on tries to tuch again such packet.\"\n\nact_ct was never meant to be used in the egress path, however some users\nare attaching it to egress today [2]. Attempting to reach a middle\nground, we noticed that, while most qdiscs are not handling\nTC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we\naddress the issue by only allowing act_ct to bind to clsact/ingress\nqdiscs and shared blocks. That way it's still possible to attach act_ct to\negress (albeit only with clsact).\n\n[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/\n[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/act_api.h", "net/sched/act_ct.c", "net/sched/cls_api.c"], "versions": [{"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6", "lessThan": "524ce8b4ea8f64900b6c52b6a28df74f6bc0801e", "status": "affected", "versionType": "git"}, {"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6", "lessThan": "380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6", "status": "affected", "versionType": "git"}, {"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6", "lessThan": "9deda0fcda5c1f388c5e279541850b71a2ccfcf4", "status": "affected", "versionType": "git"}, {"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6", "lessThan": "11cb63b0d1a0685e0831ae3c77223e002ef18189", "status": "affected", "versionType": "git"}, {"version": "172ba7d46c202e679f3ccb10264c67416aaeb1c4", "status": "affected", "versionType": "git"}, {"version": "0b5b831122fc3789fff75be433ba3e4dd7b779d4", "status": "affected", "versionType": "git"}, {"version": "73f7da5fd124f2cda9161e2e46114915e6e82e97", "status": "affected", "versionType": "git"}, {"version": "f5346df0591d10bc948761ca854b1fae6d2ef441", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/act_api.h", "net/sched/act_ct.c", "net/sched/cls_api.c"], "versions": [{"version": "6.8", "status": "affected"}, {"version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.77", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.18", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.8", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0-rc3", "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": "6.8", "versionEndExcluding": "6.12.77"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.18.18"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.19.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.0-rc3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.148"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.75"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.14"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/524ce8b4ea8f64900b6c52b6a28df74f6bc0801e"}, {"url": "https://git.kernel.org/stable/c/380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6"}, {"url": "https://git.kernel.org/stable/c/9deda0fcda5c1f388c5e279541850b71a2ccfcf4"}, {"url": "https://git.kernel.org/stable/c/11cb63b0d1a0685e0831ae3c77223e002ef18189"}], "title": "net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks\n\nAs Paolo said earlier [1]:\n\n\"Since the blamed commit below, classify can return TC_ACT_CONSUMED while\nthe current skb being held by the defragmentation engine. As reported by\nGangMin Kim, if such packet is that may cause a UaF when the defrag engine\nlater on tries to tuch again such packet.\"\n\nact_ct was never meant to be used in the egress path, however some users\nare attaching it to egress today [2]. Attempting to reach a middle\nground, we noticed that, while most qdiscs are not handling\nTC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we\naddress the issue by only allowing act_ct to bind to clsact/ingress\nqdiscs and shared blocks. That way it's still possible to attach act_ct to\negress (albeit only with clsact).\n\n[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/\n[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/"}], "id": "CVE-2026-23270", "lastModified": "2026-03-18T18:16:26.053", "metrics": {}, "published": "2026-03-18T18:16:26.053", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/11cb63b0d1a0685e0831ae3c77223e002ef18189"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/524ce8b4ea8f64900b6c52b6a28df74f6bc0801e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9deda0fcda5c1f388c5e279541850b71a2ccfcf4"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks", "id": "2448745", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2448745"}, "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-416", "details": ["No description is available for this CVE."], "name": "CVE-2026-23270", "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": "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": "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": "2026-03-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-23270\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23270\nhttps://lore.kernel.org/linux-cve-announce/2026031847-CVE-2026-23270-cb9a@gregkh/T"], "statement": "A use after free risk exists in the traffic control act_ct path when it is attached to non ingress egress qdiscs. In this configuration classify can return TC_ACT_CONSUMED while the skb is still held by the defragmentation engine. That can result in the skb being consumed and later accessed again by defragmentation which may lead to a kernel crash. Impact is denial of service in the common case, but keeping in mind that a kernel UAF could be exploitable for privilege escalation in some cases. The bug could happen only if some specific configuration being used (when tc/action being used and if the act_ct linked to incorrect qdisc/block), and in some cases regular user (is with some privileges) can make such configuration.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f14b377d01d8357eba032b4cabc8c1149b458b6,524ce8b4ea8f64900b6c52b6a28df74f6bc0801e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f14b377d01d8357eba032b4cabc8c1149b458b6,380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f14b377d01d8357eba032b4cabc8c1149b458b6,9deda0fcda5c1f388c5e279541850b71a2ccfcf4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f14b377d01d8357eba032b4cabc8c1149b458b6,11cb63b0d1a0685e0831ae3c77223e002ef18189)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "172ba7d46c202e679f3ccb10264c67416aaeb1c4"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "0b5b831122fc3789fff75be433ba3e4dd7b779d4"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "73f7da5fd124f2cda9161e2e46114915e6e82e97"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "f5346df0591d10bc948761ca854b1fae6d2ef441"}}], "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": "6.8"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.8)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.77,6.13.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.18,6.19.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.19.8,6.20.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0-rc3,*]"}}], "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": "2026-03-19T08:55:48.729801+00:00", "updated": "2026-03-19T08:55:48.729938+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}