Skip to main content
VulnerabilityPublished Updated

CVE-2026-98959: Linux kernel · btrfs: fix xattr replace when multiple xattrs are packed in the same item

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in c1803697a60f22743aa28ad522f805e92d45e3f0 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.6% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in c1803697a60f22743aa28ad522f805e92d45e3f0, a97114b9b00ed3d05156f3b2ddbf797296260389, 5877d7138cc4359d26fd7b010eedfd1b3162348f +6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 23 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • >=3.10.83 <3.11
  • >=3.12.45 <3.13
  • >=3.14.47 <3.15
  • >=3.18.19 <3.19
Fixed in
  • c1803697a60f22743aa28ad522f805e92d45e3f0
  • a97114b9b00ed3d05156f3b2ddbf797296260389
  • 5877d7138cc4359d26fd7b010eedfd1b3162348f
  • 858bee1c77857aabcc2327cd32dd8266332de332
  • 7a53bb4668b319fc6c8a3ce2c21635125c7d2712
  • 3.19
  • 3.15
  • 3.13
  • 3.11
LinuxLinuxAffected
  • =3.19
Fixed in–

AI-suggested

This vulnerability has been fixed in Linux kernel versions 3.11, 3.13, 3.15, and 3.19 and corresponding commits. Users should upgrade to these fixed versions or later to remediate the issue. No additional mitigation steps are required once the system is updated.

Description

CVE-2026-98959 is a critical vulnerability in the Linux kernel's Btrfs filesystem related to extended attribute (xattr) handling. When multiple xattrs are packed in the same btrfs_dir_item and one xattr is replaced with a value of a different size, the kernel fails to fully initialize the new btrfs_dir_item. This causes filesystem corruption detected during extent buffer writeback, leading to transaction aborts and potential data loss. The issue occurs because the deletion and insertion of xattr items shift data in the leaf, leaving parts uninitialized. The vulnerability affects multiple Linux kernel versions prior to 3.11, 3.13, 3.15, and 3.19, with fixes applied in those versions. The CVSS 3.1 score is 9.8, indicating critical severity.

References

Community reviews

Loading reviews…