SB20260905109 - Out-of-bounds write in Linux kernel ipv6

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Main Vulnerability Database SB20260905109

SB20260905109 - Out-of-bounds write in Linux kernel ipv6

Published: September 5, 2026

Security Bulletin ID SB20260905109
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds write (CVE-ID: CVE-2026-80840)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause an out-of-bounds write.

The vulnerability exists due to improper initialization of the IPv4 control block in the IPv6 Segment Routing decapsulation path when processing a specially crafted IPv6 packet containing an encapsulated IPv4 TCP SYN packet. A remote attacker can send a specially crafted packet with controlled IPv6 extension-header and IPv4 option data to cause an out-of-bounds write.


Remediation

Install update from vendor's website.

References