Linux Kernel up to 6.6.134/6.12.81/6.18.22/6.19.12 X.509 Certificate out-of-bounds

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.6.134/6.12.81/6.18.22/6.19.12. Impacted is an unknown function of the component X.509 Certificate Handler. This manipulation causes out-of-bounds. This vulnerability is tracked as CVE-2026-31430. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.134/6.12.81/6.18.22/6.19.12. It has been declared as problematic. Affected by this vulnerability is some unknown functionality of the component X.509 Certificate Handler. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: X.509: Fix out-of-bounds access when parsing extensions Leo reports an out-of-bounds access when parsing a certificate with empty Basic Constraints or Key Usage extension because the first byte of the extension is read before checking its length. Fix it. The bug can be triggered by an unprivileged user by submitting a specially crafted certificate to the kernel through the keyrings(7) API. Leo has demonstrated this with a proof-of-concept program responsibly disclosed off-list.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-31430 since 03/09/2026. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 307607 (Linux Distros Unpatched Vulnerability : CVE-2026-31430), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.135, 6.12.82, 6.18.23 or 6.19.13 eliminates this vulnerability. Applying the patch 672b526def1f94c1be8eb11b885b803da0d8c2f1/30ab358fad0c7daa1d282ec48089901b21b36a20/206121294b9cf27f0589857f80d64f87e496ffb2/7fb4dadc2734f4020d7543d688b8d49c8e569c61/d702c3408213bb12bd570bb97204d8340d141c51 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 (307607), EUVD (EUVD-2026-23819) and CERT Bund (WID-SEC-2026-1180). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.1
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 307607
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-31430

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.135/6.12.82/6.18.23/6.19.13
Patch: 672b526def1f94c1be8eb11b885b803da0d8c2f1/30ab358fad0c7daa1d282ec48089901b21b36a20/206121294b9cf27f0589857f80d64f87e496ffb2/7fb4dadc2734f4020d7543d688b8d49c8e569c61/d702c3408213bb12bd570bb97204d8340d141c51

Timelineinfo

03/09/2026 CVE reserved
04/20/2026 +41 days Advisory disclosed
04/20/2026 +0 days VulDB entry created
05/21/2026 +31 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-31430 (🔒)
GCVE (CVE): GCVE-0-2026-31430
GCVE (VulDB): GCVE-100-358297
EUVD: 🔒
CERT Bund: WID-SEC-2026-1180 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 04/20/2026 12:35
Updated: 05/21/2026 23:35
Changes: 04/20/2026 12:35 (58), 04/20/2026 14:00 (7), 04/20/2026 16:24 (1), 04/21/2026 02:03 (2), 05/21/2026 23:35 (11)
Complete: 🔍
Cache ID: 216::103

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

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Are you interested in using VulDB?

Download the whitepaper to learn more about our service!