Zammad GmbH Zammad Session Fixation Vulnerability

🚨SEVERITY: CRITICAL — CVSS 9.4Security Advisory

TL;DR 📌

  • 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.
  • Highest CVSS: 9.4 (Critical).
  • Listed in CISA KEV (2026-10-02) — this is being exploited in the wild.
  • Check the advisory for fixed releases — remediation detail is in the vendor link below.
  • CVEs: CVE-2026-102489.

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.

For leadership 🧭

Executive summary. Risk is Critical (CVSS 9.4) across any Zammad GmbH kit you run. Follow the remediation in the vendor advisory within Immediate — CISA KEV entries carry a federal remediation deadline.

Why it matters:

  • Exposure depends on deployment topology and which access paths reach the affected component.
  • Treat internet-facing and management-plane instances as higher risk than internal-only ones.
  • Keep monitoring for abnormal authentication and configuration events until upgrades complete.

Now / Next / Later:

  • Now: confirm whether you run the affected versions, and check exposure of any that are internet-facing.
  • Next: apply the remediation the advisory specifies, through an approved change window.
  • Later: add a control check so builds cannot drift back onto a vulnerable train.

Source