PatchTheCVECVE-2026-102489: Zammad GmbH Zammad Session Fixation Vulnerability
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CRITICAL 9.8EXPLOITEDREMOTEUPGRADE
CVE-2026-102489 is a critical-severity flaw (CVSS 9.8) affecting zammad, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Critical severity
- Exploited in the wild (CISA KEV)
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.3% (top 31%) |
| CISA exploited list | Yes, fix due 2026-10-05 |
| Weakness | CWE-384 |
| Published | 2026-09-30 |
| Last modified | 2026-10-10 |
Publisher (CNA): Dutch Institute for Vulnerability Disclosure · Vendor: zammad
Am I affected?
Timeline
- Published CVE record published
- Exploited Added to the CISA Known Exploited Vulnerabilities list
- Deadline CISA due date for US federal agencies to patch
- Updated Record last modified
zammad zammad UPGRADE
Affected: >= 6.3.0 and <= 6.5.4
Fixed in: newer than 6.5.4
Safe to downgrade to: a release before 6.3.0
1. Check installed version
apt-cache policy zammad || rpm -q zammad || zammad --version
2. UPGRADE to newer than 6.5.4 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade zammad
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade zammad
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 6.3.0 (Debian / Ubuntu)
apt-cache madison zammad
sudo apt install zammad=<VERSION_BEFORE_6.3.0>
sudo apt-mark hold zammad
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list zammad
sudo dnf downgrade zammad-<VERSION_BEFORE_6.3.0>
sudo dnf versionlock add zammad
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Exact fixes by distribution
Fedora 46 · retext · FIXED · 8.1.0-1.fc46 · FEDORA-2026-0602a84203 · source
sudo dnf upgrade --advisory=FEDORA-2026-0602a84203
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- GitHub PoC: horizon3ai/CVE-2026-102489 (6 stars)
- GitHub PoC: 1xPwn/CVE-2026-102489 (6 stars)
- GitHub PoC: Hunt-Benito/the-cookie-in-the-error-message-cve-2026-102489-zammad-session-hijack-to-rce (0 stars)
Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Related CVEs
- CVE-2026-102490 HIGH 7.8 EXPLOITED UPGRADE Zammad GmbH Zammad Improper Privilege Management Vulnerability