Mattermost
CVE-2026-1629
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Operation on resource after expiration or release
|
| Impact | CVSS score of 4.3 (MEDIUM). |
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Alert meAnalysisAIv1 – Mar 16, 2026
Mattermost 10.11.x through 10.11.10 fails to clear cached permalink preview data when a user's channel access is revoked, allowing authenticated users to view private channel content through previously cached previews until the cache expires or they re-login. An authenticated attacker who previously had access to a private channel can exploit this to maintain visibility into sensitive channel communications after access removal. A patch is not currently available for this medium-severity vulnerability.
Earlier versions of this analysis (1)
RemediationAI
Monitor vendor advisories for patches. Apply mitigations such as network segmentation, access restrictions, and monitoring.
Affects your stack
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Technical ContextAI · show details
This vulnerability is classified as Operation on a Resource after Expiration or Release (CWE-672).
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
Mattermost versions 10.11.x <= 10.11.10 Fail to invalidate cached permalink preview data when a user loses channel access which allows the user to continue viewing private channel content via previously cached permalink previews until cache reset or relogin.. Mattermost Advisory ID: MMSA-2026-00580
Executive ViewAI
CVE-2026-1629 presents moderate security risk rated CVSS 4.3. Exploitation could compromise the security of affected deployments. Organizations should apply vendor updates when available and monitor for exploitation.
Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)CVE.org
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NVD
CVE.org
EPSS
VulDB
GitHub PoC
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