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VulnerabilityPublished Updated

CVE-2026-46046: Linux kernel · ext4: fix missing brelse() in ext4_xattr_inode_dec_ref_all()

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 5.5 Medium · fixed in 7.0.0-27.27 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score
5.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 7.0.0-27.27, 7.0.0-1008.8, 7.0.0-1007.7 +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 May 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
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux@7.0.0-27.27?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-27.27
Fixed in
  • 7.0.0-27.27
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@7.0.0-1008.8?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1008.8
Fixed in
  • 7.0.0-1008.8
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@7.0.0-1009.9?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1009.9
10 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1008.8
4 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp@7.0.0-1007.7?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1007.7
Fixed in
  • 7.0.0-1007.7
Ubuntu 26.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm@7.0.0-1009.9?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1009.9
Fixed in
  • 7.0.0-1009.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available and included in Linux kernel versions after 5.15.0-186.196 and in updated packages as per the Ubuntu security advisory USN-8488-1. Users should update their Linux kernel to the fixed versions provided by their distribution. No additional mitigation is required beyond applying the official patch.

Description

A vulnerability in the Linux kernel ext4 filesystem was fixed that involved a missing brelse() call in the ext4_xattr_inode_dec_ref_all() function. This caused a refcount leak when block_csum was false, due to failure to release a buffer head obtained via ext4_get_inode_loc(). The issue was resolved in kernel versions after 5.15.0-186.196 and specific listed versions. The vulnerability has a medium severity with a CVSS score of 5.5 and impacts availability but not confidentiality or integrity.

References

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