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.
What to do
Treat this as urgent. Identify every affected system, starting with anything internet-facing, and apply the vendor fix or mitigation within days. If you cannot patch quickly, isolate or disable the affected service and watch for signs of compromise.
- Priority
- Act now: Patch or mitigate internet-facing systems within days.
- Severity (CVSS)
- 9.4 critical
- CISA assessment (SSVC)
- actively exploited; needs manual effort per target; total control of the affected system
- Exploit probability (EPSS, 30 days)
- 1.3%, higher than 68% of all CVEs
- Added to CISA KEV
- 2 October 2026
- CISA fix-by date
- 5 October 2026 (US federal agencies; a sensible deadline for everyone)
- Ransomware use
- Not known
- Weakness
- CWE-384
References
- NIST NVD entry
- CISA KEV entry
- community.zammad.org/t/take-care-local-privilege-escalation-cve-2026-102490-is-r
- csirt.divd.nl/CVE-2026-102489
- csirt.divd.nl/DIVD-2026-00015
- zammad.com/en/advisories/cve-2026-102489-cve-2026-102490
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-102489
Sources: CISA Known Exploited Vulnerabilities · FIRST Exploit Prediction Scoring System (EPSS) · NIST National Vulnerability Database · CISA Vulnrichment (SSVC), via the CVE Program. This product uses data from the NVD API but is not endorsed or certified by the NVD. Summaries are machine-written from CISA’s description; treat the vendor’s advisory as the authority for fixes.