CVE-2026-23223
HighIn the Linux kernel, the following vulnerability has been resolved: xfs: fix UAF in xchk_btree_check_block_owner We cannot dereference bs->cur when trying to determine if bs->cur aliases bs->sc->sa.{bno,rmap}_cur after the latter has been freed. Fix this by sampling before type before any freeing could happen. The correct temporal ordering was broken when we removed xfs_btnum_t.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2026-23223 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
Affected versions
Linux kernel versions
6.9
and later are affected. Fixed in
6.12.72,
6.18.11,
6.19.1,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-23223 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/1c253e11225bc5167217897885b85093e17c2217
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PatchKernel patch commithttps://git.kernel.org/stable/c/1d411278dda293a507cb794db7d9ed3511c685c6
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PatchKernel patch commithttps://git.kernel.org/stable/c/ba5264610423d9653aa36920520902d83841bcfd
Frequently asked questions
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What is CVE-2026-23223?
CVE-2026-23223 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 6.9 onward and has been patched in 6.12.72, 6.18.11, 6.19.1 and others. CVE-2026-23223 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-23223?
CVE-2026-23223 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2026-23223?
Yes — CVE-2026-23223 has been patched. Fixed versions include 6.12.72, 6.18.11, 6.19.1 and others. If you are running Linux kernel 6.9 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-23223 actively exploited?
No — CVE-2026-23223 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →