SB20260720310 - Out-of-bounds read in Linux kernel ipv6

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Main Vulnerability Database SB20260720310

SB20260720310 - Out-of-bounds read in Linux kernel ipv6

Published: July 20, 2026

Security Bulletin ID SB20260720310
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds read (CVE-ID: CVE-2026-63920)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in ip6_datagram_recv_specific_ctl() when processing IPv6 extension headers for recvmsg control messages after the hdrlen field is modified. A local user can use an nftables payload-write expression to corrupt the extension header length and trigger copying beyond the available header data to disclose sensitive information.

Exploitation is reachable from an unprivileged user namespace.


Remediation

Install update from vendor's website.

References