{"id":"CVE-2026-53239","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()\n\nFix the race by pruning the bin while still holding xfrm_policy_lock,\nbefore dropping it","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()\n\nFix the race by pruning the bin while still holding xfrm_policy_lock,\nbefore dropping it. Us…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416","CWE-364"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.0, < 5.10.259","linux_kernel >= 5.11, < 5.15.210","linux_kernel >= 5.16, < 6.1.176","linux_kernel >= 6.2, < 6.6.143","linux_kernel >= 6.7, < 6.12.94","linux_kernel >= 6.13, < 6.18.36","linux_kernel >= 6.19, < 7.0.13","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.13"],"published":"2026-06-25","updated":"2026-09-08","sourceUpdated":"2026-09-08T09:18:15.057","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53239","references":[{"url":"https://git.kernel.org/stable/c/25c8c7fb3b0b9668c7d05e209f58c158d2b020c7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/42827d03f8009a6a218bacab153e21f39d6a121c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7f2d76c9c03257c0782afef9d95321fa04096f60","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/88697cf980222d5906a37bf47662dac0732e2a0f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8fc536e9f6856230f19c7d13e71af064b6a77b22","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b5316e2b8614a87d8736941972441cb47bfd4491","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c4c1ea36d83bf3c4569468ca5b8b614fda1bf821","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ec82ea4eb220164d854f8734ca5a35e23e577b94","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53239.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-53239"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492779"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53239"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53239"},{"url":"https://lore.kernel.org/linux-cve-announce/2026062510-CVE-2026-53239-8ebc@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:67471"},{"url":"https://access.redhat.com/errata/RHSA-2026:68570"},{"url":"https://access.redhat.com/errata/RHSA-2026:68531"},{"url":"https://access.redhat.com/errata/RHSA-2026:68532"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00128,"epssPercentile":0.02784,"ingestedAt":"2026-09-08T15:33:26.944Z","scores":{"nvd":7.8,"vendor":7},"slug":"CVE-2026-53239","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()\n\nFix the race by pruning the bin while still holding xfrm_policy_lock,\nbefore dropping it. Use __xfrm_policy_inexact_prune_bin() directly since\nthe lock is already held. The wrapper xfrm_policy_inexact_prune_bin()\nbecomes unused and is removed.\n\nRace:\n\n  CPU0 (XFRM_MSG_DELPOLICY)           CPU1 (XFRM_MSG_NEWSPDINFO)\n  ==========================          ==========================\n  xfrm_policy_bysel_ctx():\n    spin_lock_bh(xfrm_policy_lock)\n    bin = xfrm_policy_inexact_lookup()\n    __xfrm_policy_unlink(pol)\n    spin_unlock_bh(xfrm_policy_lock)\n    xfrm_policy_kill(ret)\n    // wide window, lock not held\n                                       xfrm_hash_rebuild():\n                                         spin_lock_bh(xfrm_policy_lock)\n                                         __xfrm_policy_inexact_flush():\n                                           kfree_rcu(bin)  // bin freed\n                                         spin_unlock_bh(xfrm_policy_lock)\n    xfrm_policy_inexact_prune_bin(bin)\n    // UAF: bin is freed\n\n## Affected\n\n- `linux_kernel >= 5.0, < 5.10.259`\n- `linux_kernel >= 5.11, < 5.15.210`\n- `linux_kernel >= 5.16, < 6.1.176`\n- `linux_kernel >= 6.2, < 6.6.143`\n- `linux_kernel >= 6.7, < 6.12.94`\n- `linux_kernel >= 6.13, < 6.18.36`\n- `linux_kernel >= 6.19, < 7.0.13`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.13`\n\n## Vendor advisories\n\n- **RHSA-2026:67471** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67471)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53239.json)\n- **RHSA-2026:68570** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68570)\n- **RHSA-2026:68531** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68531)\n- **RHSA-2026:68532** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68532)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}