CVE-2026-121617: Linksys E5600 Header upload_fw.cgi init_multipart out-of-bounds write
A security flaw has been discovered in Linksys E5600 1.1.0.26. Affected by this issue is the function initmultipart of the file /cgi-bin/uploadfw.cgi of the component Header Parser. The manipulation results in out-of-bounds write. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way. This vulnerability only affects products that are no longer supported by the maintainer.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Linksys E5600 devices running version 1.1.0.26 are identified as affected. The issue is limited to products that are no longer supported by the maintainer.
Does an attacker need credentials or user interaction?
No. The supplied vector indicates network-reachable exploitation with low attack complexity, no privileges, and no user interaction required.
Is public exploit code available?
Yes. A proof-of-concept exploit has been publicly released and may be used in attacks.
What is the likely impact of successful exploitation?
The issue is an out-of-bounds write in the Header Parser's init_multipart function, and the provided severity vector rates the impact as high for availability. The supplied vector does not indicate confidentiality or integrity impact.