CVE-2026-2578
Burn-on-Read Data Exposure via Post Deletion in Mattermost
Publication date: 2026-03-16
Last updated on: 2026-03-18
Assigner: Mattermost, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mattermost | mattermost_server | From 11.3.0 (inc) to 11.3.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-201 | The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects Mattermost versions 11.3.x up to and including 11.3.0. It occurs because the software fails to maintain the redacted state of burn-on-read posts when they are deleted. As a result, channel members can access the contents of these burn-on-read messages, which were supposed to remain unrevealed, through the WebSocket post deletion event.
How can this vulnerability impact me? :
The impact of this vulnerability is that sensitive information intended to be hidden or ephemeral in burn-on-read posts can be exposed to channel members. This could lead to unauthorized disclosure of confidential or private message contents, potentially compromising privacy and security within the affected Mattermost channels.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know