What is CVE-2026-22903?

CVE-2026-22903 is a critical-severity vulnerability in Wago 0852-1322, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-02-09.

How severe is CVE-2026-22903?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Wago 0852-1322

CVE-2026-22903

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 co…

Vulnerability class: Buffer Overflow

EPSS: 0.007 (47.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Wago 0852-1322 — versions 0.0.0, 2.64
Wago 0852-1328 — versions 0.0.0, 2.64

Weakness classification (CWE)

CWE-121 — Stack-based Buffer Overflow

References

info@cert.vde.com

Frequently asked questions

What is CVE-2026-22903?: CVE-2026-22903 is a critical-severity vulnerability in Wago 0852-1322, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-02-09.
How severe is CVE-2026-22903?: Critical severity. CVSS v3 base score is 9.8 out of 10.