CVE-2026-102489: Zammad GmbH Zammad Session Fixation Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by DIVD, published 2026-09-30).
Weakness: CWE-384 Session Fixation
How it can be exploited
Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and a user must take an action. Impact: confidentiality high, integrity high, availability high. 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
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2026-10-02
- US federal deadline
- 2026-10-05
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: EUVD-2026-90080, GHSA-xmw5-m2wg-4243
VEDAS cluster: VEDAS:BARNBOUND
Exploit Observer links 4 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (4)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Nuclei template: https://raw.githubusercontent.com/projectdiscovery/nuclei-templates/main/websocket/cves/2026/CVE-2026-102489.yaml
- Code repository: https://github.com/1xpwn/cve-2026-102489
- Code repository: https://github.com/horizon3ai/cve-2026-102489
- Code repository: https://github.com/hunt-benito/the-cookie-in-the-error-message-cve-2026-102489-zammad-session-hijack-to-rce
Research and write-ups (3)
- Research or write-up: https://csirt.divd.nl/CVE-2026-102489
- Research or write-up: https://horizon3.ai/attack-research/disclosures/cve-2026-102489-zammad-session-leak-rce
- Research or write-up: https://zammad.com/en/advisories/cve-2026-102489-cve-2026-102490
Vulnerability databases and vendor advisories (4)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-90080
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-xmw5-m2wg-4243
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-102489
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-102489
News (1)
77 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.225
likely to be attacked soon - VEDAS
- 0.976
strong exploit evidence - On CISA KEV
- Yes, since 2026-10-02
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Zammad GmbH Zammad | from 6.3.0 before 6.5.4 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: zammad zammad.
How to fix it
Fixed versions stated in the CVE record: 6.5.4.
CISA required action: 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.
Vendor guidance:
- https://zammad.com/en/advisories/cve-2026-102489-cve-2026-102490 (vendor-advisory)
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Vendor advisories and patches
- https://zammad.com/en/advisories/cve-2026-102489-cve-2026-102490 (vendor-advisory)
Exploits and technical analysis
- https://csirt.divd.nl/DIVD-2026-00015 (third-party-advisory)
- https://csirt.divd.nl/CVE-2026-102489 (third-party-advisory)
- https://community.zammad.org/t/take-care-local-privilege-escalation-cve-2026-102490-is-reported-as-being-actively-exploited/21297/2 (technical-description)
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-102489 (government-resource)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.