Out-of-bounds write in Linux kernel - CVE-2026-74597

Vulnerability details

The vulnerability allows a remote attacker to corrupt memory.

The vulnerability exists due to an out-of-bounds write in ip6ip6_err() and the IPv6 ICMP error reply path when processing a quoted inner IPv6 packet after cloning an outer IPv6 ICMP error skb with stale inet6_skb_parm metadata. A remote attacker can send a specially crafted IPv6 packet to corrupt memory.

Exploitation requires the outer packet to carry a Home Address Option and a malformed inner destination-options header.

Affected software

How to mitigate CVE-2026-74597

External References

• https://git.kernel.org/stable/c/0dadb0620ab65949a8bc2439dd28ea3c942fe87d
• https://git.kernel.org/stable/c/44fe898df302e91c5ee5acbc71ffa74e78e6c183
• https://git.kernel.org/stable/c/484134e1eb07d700a73b1e4bbf3fb503e299be60
• https://git.kernel.org/stable/c/4eb15c465337b18f44716c499cd6ad63eee0ad54
• https://git.kernel.org/stable/c/64e41736a26f37ab6215bc2e6df125df05aceb08
• https://git.kernel.org/stable/c/b6816536a2990c0db44a26130a03e40b441e829b
• https://git.kernel.org/stable/c/f803c086399da277b5d0ff36a107d0f162751800
• https://git.kernel.org/stable/c/fbf40faa0414b753212494ad197542002e66ed9e

Related Security Bulletins

• Out-of-bounds write in Linux kernel ipv6
• Debian update for linux