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CVE-2026-86348

MS Calendar plugin: unrecovered handler panics from malformed post-action requests could crash the plugin process

Published: Sep 14, 2026Updated: Sep 14, 2026 Sources: CVE List NVDCWE-704
4.3MEDIUM
NVD MITRE
EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

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

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:NI:NA:L
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:LAvailability
Low
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Weaknesses

CWE-704

Affected Products

Mattermost
commercial·US
MattermostOn-premWeb App
Communications / messaging-chat

Exploitability

Official Patch Available

References

https://mattermost.com/security-updates
mattermost.com

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