CVE-2026-31430

HIGH

X.509: Fix out-of-bounds access when parsing extensions

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 7.1
EPSS 0.0001
EPSS Percentile 2.1%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Details

CWE
CWE-125
Status published
Products (14)
Linux/Linux < 6.4
Linux/Linux 30eae2b037af54b24109dcaea21db46f6285c69b - 206121294b9cf27f0589857f80d64f87e496ffb2
Linux/Linux 30eae2b037af54b24109dcaea21db46f6285c69b - 30ab358fad0c7daa1d282ec48089901b21b36a20
Linux/Linux 30eae2b037af54b24109dcaea21db46f6285c69b - 672b526def1f94c1be8eb11b885b803da0d8c2f1
Linux/Linux 30eae2b037af54b24109dcaea21db46f6285c69b - 7fb4dadc2734f4020d7543d688b8d49c8e569c61
Linux/Linux 30eae2b037af54b24109dcaea21db46f6285c69b - d702c3408213bb12bd570bb97204d8340d141c51
Linux/Linux 6.12.82 - 6.12.*
Linux/Linux 6.18.23 - 6.18.*
Linux/Linux 6.19.13 - 6.19.*
Linux/Linux 6.4
... and 4 more
Published Apr 20, 2026
Tracked Since Apr 20, 2026