Infinite loop in Linux kernel - CVE-2026-80793
Published: September 5, 2026
Vulnerability identifier: #VU147131
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2026-80793
CWE-ID: CWE-835
Exploitation vector: Remote access
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 validation of the effective MTU in ip_do_fragment() when fragmenting IPv4 packets with an effective MTU smaller than the IPv4 header length plus 8 bytes. A remote attacker can send a packet requiring fragmentation over an affected route or device to cause a denial of service.
The issue can occur while forwarding packets to a device with an MTU of 20 bytes.
Affected software
Linux kernel
How to mitigate CVE-2026-80793
Install security update from vendor's repository.
External References
- https://git.kernel.org/stable/c/3556beb8ca86677af2aca5bfbed6f8e790fccc83
- https://git.kernel.org/stable/c/36e0741833bd823866f8cb9f112f37cea1a70b60
- https://git.kernel.org/stable/c/515b6816ba0c12d8415c88e5f41e6ec029e35cfa
- https://git.kernel.org/stable/c/74ce7389f8f562d39015f59a00ef7ad6acd37803
- https://git.kernel.org/stable/c/a716a64a4ba68cd46f2745fba2b1099fe8e0aa59
- https://git.kernel.org/stable/c/b0ea911453ce7210e8200a07a94d2458bd1e6430
- https://git.kernel.org/stable/c/c0726f0caf8c6b3208552949e17d23634a2f3129
- https://git.kernel.org/stable/c/c8a74adccaf028223054633b532593101dfcc581
- https://git.kernel.org/stable/c/d9d1a676b033acabf8e5645f730486d1f8204a3f