SB20260720251 - Integer overflow in Linux kernel ipv6



SB20260720251 - Integer overflow in Linux kernel ipv6

Published: July 20, 2026

Security Bulletin ID SB20260720251
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) Integer overflow (CVE-ID: CVE-2026-63984)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to corrupt memory in a forwarded packet.

The vulnerability exists due to an integer overflow in ipv6_rpl_srh_decompress() and ipv6_rpl_srh_rcv() when processing a crafted IPv6 RPL source routing header. A remote attacker can send a specially crafted packet to corrupt memory in a forwarded packet.

The issue occurs because the computed hdrlen value can truncate to zero for a large segment count, causing the compressed header to overlap the decompressed routing data.


Remediation

Install update from vendor's website.