CVE-2026-31430
X.509: Fix out-of-bounds access when parsing extensions
Description
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.
INFO
Published Date :
April 20, 2026, 10:16 a.m.
Last Modified :
May 21, 2026, 3:28 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Validate extension length before accessing data.
- Ensure proper bounds checking for certificate extensions.
- Apply the provided patch for X.509 parsing.
Public PoC/Exploit Available at Github
CVE-2026-31430 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31430.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31430 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31430
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31430 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31430 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
May. 21, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Added CWE CWE-125 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.23 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.13 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.82 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.4 up to (excluding) 6.6.135 Added Reference Type kernel.org: https://git.kernel.org/stable/c/206121294b9cf27f0589857f80d64f87e496ffb2 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/30ab358fad0c7daa1d282ec48089901b21b36a20 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/672b526def1f94c1be8eb11b885b803da0d8c2f1 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/7fb4dadc2734f4020d7543d688b8d49c8e569c61 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d702c3408213bb12bd570bb97204d8340d141c51 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 20, 2026
Action Type Old Value New Value Added Description 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. Added Reference https://git.kernel.org/stable/c/206121294b9cf27f0589857f80d64f87e496ffb2 Added Reference https://git.kernel.org/stable/c/30ab358fad0c7daa1d282ec48089901b21b36a20 Added Reference https://git.kernel.org/stable/c/672b526def1f94c1be8eb11b885b803da0d8c2f1 Added Reference https://git.kernel.org/stable/c/7fb4dadc2734f4020d7543d688b8d49c8e569c61 Added Reference https://git.kernel.org/stable/c/d702c3408213bb12bd570bb97204d8340d141c51