Reliance on undefined behavior in Linux kernel - CVE-2026-89949
Published: September 17, 2026
Vulnerability identifier: #VU150331
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89949
CWE-ID: CWE-758
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper handling of unaligned memory access in the batman-adv distributed ARP table IP extraction functions when processing ARP packets with unaligned data in socket buffers. A remote attacker can send an ARP packet to cause a denial of service.
Only hardware without native support for unaligned reads is affected.
Affected software
Linux kernel
How to mitigate CVE-2026-89949
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/0121afa52cdb88cfb4d5d7bd126a23a9100121d8
- https://git.kernel.org/stable/c/0c2df865338bbf92aa45b9253e5f9b8ef2d9992f
- https://git.kernel.org/stable/c/15dbfb37f0e1a085d48deeb8f5238e9d28127dde
- https://git.kernel.org/stable/c/1cfa7d5f70d54cb8c7e82df739430782d1996ee1
- https://git.kernel.org/stable/c/91c99b4e152023c7d458a5dedd52d2b0d7df4ce3
- https://git.kernel.org/stable/c/a170d4617e8cca05a1314de61728a262ef272782
- https://git.kernel.org/stable/c/b1bbc694ca51adb8dbed3f3235b4fcbdb44e0e20
- https://git.kernel.org/stable/c/c74a4acf41d19f21199dec2d6c813c90d31cd02c