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CVE-2026-3590

Race Condition in Guest Magic Link Authentication Allows Token Reuse

Published: Apr 15, 2026Updated: Apr 22, 2026 Sources: CVE List NVD BDUCWE-367
6.5MEDIUM
NVD MITRE
EPSS Score
0.1%
Top 95.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

Description

Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-367

Affected Products

Mattermost
commercial·US
MattermostOn-premWeb App
Communications / messaging-chat
mattermost serverOn-premWeb App
Communications / messaging-chat
Mattermost Inc
commercial·USaka mattermost
MattermostOn-premWeb App
Communications / messaging-chat

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique
Privilege Escalation
View detailed technique mapping

References

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