Use After Free in Linux

CVE-2026-23223

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.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (1.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23223: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23223?
CVE-2026-23223 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2026-02-18.
How severe is CVE-2026-23223?
High severity. CVSS v3 base score is 7.8 out of 10.