Zammad: 2 flaws used in attacks; attackers can run their own code
OFFICIAL NAMES: Zammad GmbH Zammad Improper Privilege Management Vulnerability · Zammad GmbH Zammad Session Fixation Vulnerability
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TECHNICAL SUMMARY 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.
WHY THIS VERDICT Attacks are confirmed. The vulnerability is 41 days old, so many systems are likely still unpatched.
WHY IT RANKS HERE Exploitation is confirmed by an authoritative source.
- HIGHEST CONFIRMED RUNG
- EXPLOITED
- CISA KEV
- LISTED
- EXPLOIT CODE
- PROOF OF CONCEPT CLAIMED
How far has it climbed?
01 TALK
▨ REPORTED, NOT CONFIRMEDNEWEST EVIDENCE · 1 SOURCECVE-2026-102490 discussed publicly (CIRCL sighting). CVE-2026-102489 discussed publicly (CIRCL sighting).
02 EXPOSED
□ NOT TRACKED YETNO SOURCE FOR THIS STEP YETWe have no source that counts exposed systems yet. Internet scan data needs a partnership we do not have. No evidence here does not mean nothing is exposed.
03 TRIED
■ CONFIRMEDNEWEST EVIDENCE · 2 INDEPENDENT SOURCESAttacks that worked are confirmed (step 4), so attempts count as confirmed too.
- SRC: CISA Known Exploited Vulnerabilities: Zammad GmbH Zammad Session Fixation Vulnerability · OCT 1
- SRC: CISA Known Exploited Vulnerabilities: Zammad GmbH Zammad Improper Privilege Management Vulnerability · OCT 1
- SRC: CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-102490 as actively exploited · SEP 30
- SRC: CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-102489 as actively exploited · SEP 30
04 EXPLOITED
■ CONFIRMEDNEWEST EVIDENCE · 2 INDEPENDENT SOURCESZammad 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. Zammad GmbH Zammad contains an improper privilege management vulnerability that can allow the local zammad user to escalate privileges to root. This vulnerability can be chained with CVE-2026-102489.
- SRC: CISA Known Exploited Vulnerabilities: Zammad GmbH Zammad Session Fixation Vulnerability · OCT 1
- SRC: CISA Known Exploited Vulnerabilities: Zammad GmbH Zammad Improper Privilege Management Vulnerability · OCT 1
- SRC: CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-102490 as actively exploited · SEP 30
- SRC: CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-102489 as actively exploited · SEP 30
05 DAMAGE
□ NOT TRACKED YETNO SOURCE FOR THIS STEP YETBreach notices and filings rarely name the flaw that was used, so we cannot link them to this event yet. No evidence here does not mean no harm.
When each thing happened
- DISCLOSED
- EXPLOIT CODE PUBLICCLAIMED
- FIRST ATTACK REPORT
- CISA KEV LISTING
- US FEDERAL DEADLINE
THE FIX
CISA's instruction: apply the vendor's fix, or stop using the product if no fix exists. The deadline CISA set for US federal agencies, Oct 5, 2026, has passed. It is a US government deadline; use it as a guide.
Questions to ask this week
- Do we run Zammad? If yes, is it patched or cut off from the internet?
- Who owns fixing it, and by what date?
- Have we checked for signs of attack since the first report, not just since the patch?
How it unfolded
- Attack activity. SEP 30, 2026CISA Vulnrichment marks CVE-2026-102489 as actively exploited
- Attack activity. SEP 30, 2026CISA Vulnrichment marks CVE-2026-102490 as actively exploited
- Attack activity. OCT 1, 2026Zammad GmbH Zammad Session Fixation Vulnerability
- Attack activity. OCT 1, 2026Zammad GmbH Zammad Improper Privilege Management Vulnerability
- OCT 6, 20263 public GitHub repositories claim a proof of concept for CVE-2026-102489
- NOV 9, 2026CVE-2026-102489 discussed publicly (CIRCL sighting)
- NOV 9, 2026CVE-2026-102490 discussed publicly (CIRCL sighting)
SOURCES
- [1] CIRCL Vulnerability-Lookup sightings: CVE-2026-102490 discussed publicly (CIRCL sighting), NOV 9
- [2] PoC-in-GitHub: 3 public GitHub repositories claim a proof of concept for CVE-2026-102489, OCT 6
- [3] CISA Known Exploited Vulnerabilities: Zammad GmbH Zammad Session Fixation Vulnerability, OCT 1
- [4] CISA Known Exploited Vulnerabilities: Zammad GmbH Zammad Improper Privilege Management Vulnerability, OCT 1
- [5] CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-102490 as actively exploited, SEP 30
- [6] CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-102489 as actively exploited, SEP 30