CVE-2026-80961

High

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate kset key_num and intra-segment bounds Two more fields decoded from the cache device go unbounded. The kset key_num drives cache_kset_crc() and the replay loop in cache_replay(), the writeback worker and the GC worker, but only the magic and a fixed-seed CRC are checked first, so a non-last kset whose key_num exceeds the PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare. A key's intra-segment offset and length in cache_key_decode() are taken verbatim, so a key running past its segment is replayed into the cache tree and the data CRC check and every later read hit then copy adjacent persistent memory into the caller's bio -- an out-of-bounds read that leaks to user space. Both fields are controlled by whoever supplies the cache device (CAP_SYS_ADMIN); the CRC seed is public. Add kset_onmedia_valid() to bound key_num before any kset read, and reject a key whose offset plus length, computed in 64 bits, exceeds the segment data_size. Valid metadata is unaffected.

Package Linux Kernel
Published 2026-09-11
Last modified 2026-09-13
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 6.18 and later are affected. Fixed in 6.18.50, 7.2.4, 7.3-rc1 and their respective stable series.

Affected from
≥ 6.18
Fixed in
✓ 6.18.50 6.18.x ✓ 7.2.4 7.2.x ✓ 7.3-rc1

Frequently asked questions

  • What is CVE-2026-80961?

    CVE-2026-80961 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 6.18 onward and has been patched in 6.18.50, 7.2.4 and 7.3-rc1. CVE-2026-80961 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-80961?

    CVE-2026-80961 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-2026-80961?

    Yes. CVE-2026-80961 has been patched. Fixed versions include 6.18.50, 7.2.4 and 7.3-rc1. If you are running Linux kernel 6.18 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-80961 actively exploited?

    No. CVE-2026-80961 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.