CVE-2026-22903: Stack Overflow via SESSIONID Cookie in lighttpd

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-09 · updated 2026-06-17
Weakness: CWE-121

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.

Affected products

WAGO 0852-1322: through 2.64; 2.64
WAGO 0852-1328: through 2.64; 2.64

References

https://certvde.com/de/advisories/VDE-2026-004

Get alerted when CVE-2026-22903 or the next vulnerability affects your stack