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CVE Record

CVE-2026-23223: xfs: fix UAF in xchk_btree_check_block_owner

In 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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2026-23223 is a Linux kernel XFS filesystem bug involving use-after-free memory access during an internal block-owner check. The public record confirms a fix but does not provide CVSS, impact severity, or evidence of active exploitation.

Executive priority

Track as a kernel memory-safety issue with incomplete severity data. Prioritize normal patch management, escalating for high-value Linux systems using XFS. There is no cited active exploitation in the supplied sources.

Technical view

The issue is in xfs xchk_btree_check_block_owner. The kernel fix avoids dereferencing bs->cur after related scrub cursors may have been freed by sampling the type before freeing can occur. The flaw was introduced by a temporal-ordering change after xfs_btnum_t removal.

Likely exposure

Exposure is limited to Linux kernels containing the affected XFS code paths. The bundled data lists Linux kernel versions and stable commits but does not map them cleanly to distributions. Systems using XFS should be checked first.

Exploitation context

The source bundle does not cite KEV listing, public exploitation, exploit code, or real-world attacks. Treat exploitation status as unconfirmed. Kernel use-after-free issues can be serious, but operational impact is not established in the supplied sources.

Researcher notes

The strongest evidence is the upstream Linux stable fix text. The source data has no CVSS, CWE, exploitability analysis, or distro mapping. Affected-version entries appear broad and should be reconciled against vendor kernels and backports.

Mitigation direction

  • Apply vendor kernel updates that include the referenced stable XFS fixes.
  • Prioritize Linux systems that use XFS filesystems.
  • Check distribution advisories for backported fixes and package names.
  • Avoid claiming remediation complete based only on upstream version numbers.

Validation and detection

  • Inventory Linux kernel versions across affected assets.
  • Identify systems with mounted or provisioned XFS filesystems.
  • Confirm vendor advisories include CVE-2026-23223 or the referenced commits.
  • Verify updated kernels are installed and running after reboot.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2026-23223 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxec793e690f801d97a7ae2a0d429fea1fee4d44aa, ec793e690f801d97a7ae2a0d429fea1fee4d44aa, ec793e690f801d97a7ae2a0d429fea1fee4d44aa, ec793e690f801d97a7ae2a0d429fea1fee4d44aaunaffected
LinuxLinux6.9, 0, 6.12.72, 6.18.11, 6.19.1, 7.0affected
Weakness

CWE details

No CWE listed

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