Linux Kernel up to 6.6.135/6.12.83/6.18.24/7.0.1 fuse_add_dirent_to_cache namelen deserialization

CVSS Meta Temp Score
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CTI Interest Score
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7.7$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.6.135/6.12.83/6.18.24/7.0.1. Impacted is the function fuse_add_dirent_to_cache. Performing a manipulation of the argument namelen results in deserialization. This vulnerability is known as CVE-2026-31694. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.135/6.12.83/6.18.24/7.0.1. This affects the function fuse_add_dirent_to_cache. The manipulation of the argument namelen with an unknown input leads to a deserialization vulnerability. CWE is classifying the issue as CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fuse: reject oversized dirents in page cache fuse_add_dirent_to_cache() computes a serialized dirent size from the server-controlled namelen field and copies the dirent into a single page-cache page. The existing logic only checks whether the dirent fits in the remaining space of the current page and advances to a fresh page if not. It never checks whether the dirent itself exceeds PAGE_SIZE. As a result, a malicious FUSE server can return a dirent with namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB page systems this causes memcpy() to overflow the cache page by 24 bytes into the following kernel page. Reject dirents that cannot fit in a single page before copying them into the readdir cache.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-31694 since 03/09/2026. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 322930 (SUSE SLES15: kernel-livepatch-5_14_21-150400_24_179-default / etc (SUSE-SU-2026:2601-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.136, 6.12.84, 6.18.25, 7.0.2 or 7.1-rc1 eliminates this vulnerability. Applying the patch d23ad78bfd205eac26766e38ba7d79f279131098/45c05af36311624c1148123caeb011312495d86b/7de93abfaae1b2dc94da8a07a36421bd073f1d8f/474ce83c96a55f2eeb14dee2be375eeadfdacdf5/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (322930) and CERT Bund (WID-SEC-2026-1346). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure Linux
  • Red Hat OpenShift

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 322930
Nessus Name: SUSE SLES15: kernel-livepatch-5_14_21-150400_24_179-default / etc (SUSE-SU-2026:2601-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.136/6.12.84/6.18.25/7.0.2/7.1-rc1
Patch: d23ad78bfd205eac26766e38ba7d79f279131098/45c05af36311624c1148123caeb011312495d86b/7de93abfaae1b2dc94da8a07a36421bd073f1d8f/474ce83c96a55f2eeb14dee2be375eeadfdacdf5/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed

Timelineinfo

03/09/2026 CVE reserved
05/01/2026 +52 days Advisory disclosed
05/01/2026 +0 days VulDB entry created
06/30/2026 +60 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-31694 (🔒)
GCVE (CVE): GCVE-0-2026-31694
GCVE (VulDB): GCVE-100-360585
CERT Bund: WID-SEC-2026-1346 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 05/01/2026 16:42
Updated: 06/30/2026 19:47
Changes: 05/01/2026 16:42 (59), 05/04/2026 14:10 (7), 06/04/2026 05:24 (11), 06/09/2026 02:57 (1), 06/22/2026 04:33 (1), 06/26/2026 17:23 (2), 06/30/2026 19:47 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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