CVE-2026-22903 Stack Overflow via SESSIONID Cookie in lighttpd
An unauthenticated attacker can cause a stack overflow via a long SESSIONID cookie, leading to crashes or potential remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-22903?
CVE-2026-22903 is a critical memory corruption vulnerability in WAGO 0852-1322, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An unauthenticated remote attacker can send a crafted HTTP request containing an overly long SESSIONID cookie. This can trigger a stack buffer overflow in the modified lighttpd server, causing it to crash and potentially enabling remote code execution due to missing stack protections.
Weakness: CWE-121
Which versions are affected by CVE-2026-22903?
How do I fix CVE-2026-22903?
No fix has been published for CVE-2026-22903 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-22903 being exploited?
There is no known exploitation of CVE-2026-22903 in the wild and no public exploit code.
Sources
Also known as GHSA-23jw-jg3f-6352.