CVE-2026-86348 json
MS Calendar plugin: unrecovered handler panics from malformed post-action requests could crash the plugin process
published 2026-09-14 55 d ago modified 2026-10-14 25 d ago also EUVD-2026-77481
- cvss
- 4.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 30%
- public exploits
- 0
- none known
Summary
Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover from handler panics, which allows an authenticated user to crash the plugin via a post-action request with an unexpected field type.. Mattermost Advisory ID: MMSA-2026-00701
Patch / fix
- Mattermost Mattermost 10.11.23, 11.7.8, 11.8.5, 11.9.1, 11.10.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 55 d ago
Exploit prediction
0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-704 Incorrect Type Conversion or Cast
References
-
mattermost.com
/security-updates
vendor-advisory
Sources
- CVE List CVE-2026-86348
- NVD CVE-2026-86348
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