CVE-2026-22903Network attack vector

Remote code execution via oversized SESSIONID cookie

Published Feb 9, 2026 · Updated Feb 9, 2026

Stack-based buffer overflow in WAGO 0852-1322 and 0852-1328 firmware 2.64 and earlier allows remote attackers to crash the web service. The modified lighttpd server processes an overly long SESSIONID cookie without adequate length handling, overflowing a stack buffer. No authentication or user interaction is required; missing stack protections also expose arbitrary code execution, not only a service crash.

CVSS severity9.8
Critical
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in WAGO 0852-1322 and 0852-1328 firmware 2.64 and earlier allows remote attackers to crash the web service. The modified lighttpd server processes an overly long SESSIONID cookie without adequate length handling, overflowing a stack buffer. No authentication or user interaction is required; missing stack protections also expose arbitrary code execution, not only a service crash.

The record

CVE
CVE-2026-22903
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
WAGO
Product
Industrial Managed Switch 852-1322
Classifications
CWE-121, T1499.004, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.0.0 <=2.64
  2. Affected versionversion=2.64

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WAGO · Industrial Managed Switch 852-1322version=0.0.0 <=2.64; version=2.64
WAGO · Industrial Managed Switch 852-1328version=0.0.0 <=2.64; version=2.64

Published CVSS scores

9.8CERT@VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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