cbcvebase.
CVE-2026-2578
published 2026-03-16

CVE-2026-2578: Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access…

medium4.3CVSS 3.1
AVNACLPRLUINSUCLINAN
Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579

Affected

10 ranges
VendorProductVersion rangeFixed in
github.commattermost_mattermost-server>= 0 < 5.3.2-0.20260127062706-c6b205f0d7705.3.2-0.20260127062706-c6b205f0d770
github.commattermost_mattermost-server>= 10.11.0-rc1 < 10.11.1110.11.11
github.commattermost_mattermost-server>= 10.11.0-rc1+incompatible < 10.11.11+incompatible10.11.11+incompatible
github.commattermost_mattermost-server>= 11.2.0-rc1 < 11.2.311.2.3
github.commattermost_mattermost-server>= 11.2.0-rc1+incompatible < 11.2.3+incompatible11.2.3+incompatible
github.commattermost_mattermost-server>= 11.3.0-rc1 < 11.3.111.3.1
github.commattermost_mattermost-server>= 11.3.0-rc1+incompatible < 11.3.1+incompatible11.3.1+incompatible
github.commattermost_mattermost_server_v8>= 0 < 8.0.0-20260127062706-c6b205f0d7708.0.0-20260127062706-c6b205f0d770
mattermostmattermost11.3.0 – 11.3.0
mattermostmattermost_server>= 11.3.0 < 11.3.111.3.1