VulnTideExploited vulnerabilities, by vendor. Data as of 28 Oct 2026.
Known exploitedIn CISA's KEV catalog since 2 October 2026Ransomware use: unknown
Zammad GmbH Zammad

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

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 2 Oct 2026, 2 days after the CVE record was published.

How likely is exploitation in the next 30 days?
2%

EPSS score, percentile 80.2 of all scored records

How severe?
8.7 High

CVSS v4.0 base score, given by the CNA

What should I do?

CISA deadline 5 Oct 2026. Apply mitigations in accordance with vendor instructions … Full text

Advisories and patches (1)

Which versions are affected?

Affected

  • from 6.3.0 to before 6.5.4

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

Required action, set by CISA

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.

CISA due date for this action: 5 October 2026.

Advisories and patches

Linked from CISA's catalog entry

Affected products and versions

As listed in the CVE record.

Zammad GmbH Zammad
StatusVersions
Unknownfrom * to before 6.3.0
Affectedfrom 6.3.0 to before 6.5.4
Unknownfrom 7.0.0 to before 7.1.3

Versions not listed are: unaffected.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

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.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

  • CISA added CVE-2026-102489 to its Known Exploited Vulnerabilities (KEV) catalog on 2 Oct 2026.
  • CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
  • The due date CISA sets for the required action is 5 Oct 2026.
  • The CVE record was published on 30 Sep 2026, 2 days before it was added to KEV.
  • The CVE record carries a CVSS v4.0 base score of 8.7 (High), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 2% (percentile 80.2), as of 28 Oct 2026.
  • CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

Undisclosed RCE in Zammad v6.3 and higher

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.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

DateEvent
30 Sep 2026CVE record published
2 Oct 2026Added to CISA KEV
5 Oct 2026CISA due date for the required action
19 Oct 2026CVE record last updated

References

More exploited Zammad vulnerabilities

  • CVE-2026-102490: Zammad GmbH Zammad Improper Privilege Management Vulnerability (added 2 Oct 2026)