CVE-2026-3109 json
Missing timestamp validation in Zoom webhook handler
published 7mo ago modified 4mo ago also EUVD-2026-16236
- cvss
- 2.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584
Patch / fix
- Mattermost Mattermost 10.11.12, 11.5.0
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7mo ago
Exploit prediction
0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 2.2 | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-754 Improper Check for Unusual or Exceptional Conditions
References
-
mattermost.com
/security-updates
vendor-advisory
Sources
- CVE List CVE-2026-3109
- NVD CVE-2026-3109
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