CVE-2026-2578

mediumpriority · track · 0EPSS 0.002 · 13 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.23% (13th) EPSS

CVSS 4.3 · medium

Is it mine?

14 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

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

cvss

Technical severity, 0–10. One row per scoring source.

4.3

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.14.3mediumAV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · FSTEC (BDU) RU

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · ENISA EU

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 2.8 · impact 1.4

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:Nsecondary · OSV

v3.14mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-200USCWE-201USCWE-201US

affected products (14)

Products and version ranges known to be affected.

Mattermost Mattermost≤ 11.3.0 ≤11.3.0enisa_euvdEU
Mattermost Inc Mattermost≤ 11.3.1fstec_bduRU
Mattermost Inc Mattermost≤ 11.4.0fstec_bduRU
mattermost mattermost server11.3.0 → 11.3.1nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-server< 5.3.2-0.20260127062706-c6b205f0d770osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server10.11.0-rc1 → 10.11.11osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server10.11.0-rc1+incompatible → 10.11.11+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server11.2.0-rc1 → 11.2.3osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server11.2.0-rc1+incompatible → 11.2.3+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server11.3.0-rc1 → 11.3.1osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server11.3.0-rc1+incompatible → 11.3.1+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server/v5all versionsosvUSpkg:golang/github.com/mattermost/mattermost-server/v5
Go github.com/mattermost/mattermost-server/v6all versionsosvUSpkg:golang/github.com/mattermost/mattermost-server/v6
Go github.com/mattermost/mattermost/server/v8< 8.0.0-20260127062706-c6b205f0d770osvUSpkg:golang/github.com/mattermost/mattermost/server/v8

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-3rhr-jr63-hwq5Mattermost fails to preserve the redacted state of burn-on-read posts during deletion2026-03-16ghsa · osvUS
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
GO-2026-4734Mattermost fails to preserve the redacted state of burn-on-read posts during deletion in github.com/mattermost/mattermost-server2026-03-23vendor · osvUS
Mattermost fails to preserve the redacted state of burn-on-read posts during deletion in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/mattermost/mattermost-server/v5 before v5.3.2-0.20260127062706-c6b205f0d770.

also known as (6)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv nvd NVD CVE.org MITRE

published 2026-03-16modified 2026-06-17

references (3)

External citations — patches, advisories, analysis.

scry

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