Actively exploited · Published Sep 30, 2026 · Assigned by DIVD

CVE-2026-102489Undisclosed RCE in Zammad v6.3 and higher

High 8.7 Exploited

In plain English

A high-severity session fixation in Zammad from Zammad GmbH. Attackers are actively exploiting it in the wild (listed by CISA on October 2, 2026). The chance it is exploited in the next 30 days is estimated at 22.5% (higher than 98% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. 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.

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)22.5%top 2.3% of all CVEs
Exploited in the wildYesCISA KEV since Oct 2, 2026
Attack tooling1Public PoC

CISA guidance

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.

Federal agencies must remediate by Oct 5, 2026.

Official 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 (as reported)

VendorProductVersions
Zammad GmbH Zammad 6.3.0 – before 6.5.4

Weakness: CWE-384 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:A/AU:Y/V:C

References