CVE-2026-46046: Linux kernel · ext4: fix missing brelse() in ext4_xattr_inode_dec_ref_all()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1112.119~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- 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 5.15.0-1112.119~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2 +72
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
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
- ubuntu.com/security/CVE-2026-46046 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46046 (opens in a new tab)
- git.kernel.org/linus/77d059519382bd66283e6a4e83ee186e87e7708f (opens in a new tab)
- ubuntu.com/security/notices/USN-8488-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8489-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8488-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8507-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-46046 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- git.kernel.org/stable/c/097227f1ffe1a85bc3c359f81c71e3d40e06e920 (opens in a new tab)
- git.kernel.org/stable/c/153ab2c52355fbebcae622db8e7b506492c73a29 (opens in a new tab)
- git.kernel.org/stable/c/1bc1107a3a403a6d440673ed6666f7b07ef868a8 (opens in a new tab)
- git.kernel.org/stable/c/1e6b0a69bf2c9c819255c7566e4355536d81d9cf (opens in a new tab)
- git.kernel.org/stable/c/77d059519382bd66283e6a4e83ee186e87e7708f (opens in a new tab)
- git.kernel.org/stable/c/b706d00206a9e82362a9633efbd8b5775650169b (opens in a new tab)
- git.kernel.org/stable/c/dd98a5603a212ea9c96c6982ccdbcc748fdb9a56 (opens in a new tab)
- git.kernel.org/stable/c/f072906688933bf47fabbaf63560be03357c8298 (opens in a new tab)