Out-of-bounds read in Linux kernel - CVE-2026-43038
Published: May 2, 2026
Vulnerability identifier: #VU128879
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-43038
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in ip6_err_gen_icmpv6_unreach() when processing a forged ICMPv4 error containing a CIPSO IP option and an attacker-controlled inner IPv6 packet. A remote attacker can send a specially crafted ICMP error packet to cause a denial of service.
The issue arises because IPv4 control buffer data is reused as IPv6 control buffer data in a cloned skb, which can lead to a forged home address option offset being used during IPv6 TLV parsing.
How to mitigate CVE-2026-43038
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0452b6526b2f54b2413b9cb4ff1ea2ac542c99c7
- https://git.kernel.org/stable/c/1ceeebd5bd6d855b17a5df625109bfe29129d7cf
- https://git.kernel.org/stable/c/3d5127d998de617b130aae96b138dba22ac6a8a7
- https://git.kernel.org/stable/c/86ab3e55673a7a49a841838776f1ab18d23a67b5
- https://git.kernel.org/stable/c/a2edbb6393972a02114b6003953a5cef3104fada
- https://git.kernel.org/stable/c/a4437faf135da293d16fcc4cc607316742bd0ebb
- https://git.kernel.org/stable/c/c438ba010171b70bad22fc18b1d5bdc3627476e8
- https://git.kernel.org/stable/c/e41953e7d118e2702bcb217879c173d9d1d3cd4e