CVE-2026-102489: Zammad GmbH Zammad Session Fixation Vulnerability

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: yes — in CISA KEV since 2026-10-02
EPSS: 22.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-30 · updated 2026-10-10
Weakness: CWE-384

Description

Zammad versions 6.3.0 to 6.5.4 are vulnerable a session hijack vulnerability that leads to remote code execution as the zammad user. The bug is also present in version 7.0.0 to version 7.1.2, but not exploitable due to changes in the underlying framework.

Affected products

zammad: from 6.3.0 through 6.5.4

References

https://community.zammad.org/t/take-care-local-privilege-escalation-cve-2026-102490-is-reported-as-being-actively-exploited/21297/2
https://csirt.divd.nl/CVE-2026-102489
https://csirt.divd.nl/DIVD-2026-00015
https://zammad.com/en/advisories/cve-2026-102489-cve-2026-102490
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-102489

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