Known exploited · Zammad GmbH
CVE-2026-102489: Zammad GmbH Zammad Session Fixation Vulnerability
What it is
Zammad GmbH Zammad contains a session fixation vulnerability that can lead to remote code execution as the zammad user. This vulnerability can be chained with CVE-2026-102490.
- Vendor
- Zammad GmbH
- Product
- Zammad
- Added to KEV
- October 2, 2026
- CISA due date
- October 5, 2026
- Ransomware use
- Unknown
- Weakness
- CWE-384
What CISA requires
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Forensic triage
Yes
What to do now
- Find every instance of Zammad you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before October 5, 2026 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
- Until every instance is patched, block the attack at the edge: a WAF in blocking mode stops session fixation attempts.
References
The Dome
Block it at the edge while you patch
The Dome's WAF runs the OWASP Core Rule Set in blocking mode and stops session fixation attempts before they reach your application.
See the DomeT Academy
Train the engineers who fix it
Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.
Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.02.