CVE-2026-3108

highpriority · track · 35EPSS 0.003 · 21 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.28% (21st) EPSS

CVSS 8.8 · high

Is it mine?

19 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking.. Mattermost Advisory ID: MMSA-2026-00599

cvss

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

8.8

010

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

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9

v3.18highCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:Hsecondary · ENISA EU

v3.18highCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:Hsecondary · responsibledisclosure@mattermost.comexploitability 1.3 · impact 6

v3.18highCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:Hsecondary · OSV

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

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

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-150USCWE-150US

affected products (19)

Products and version ranges known to be affected.

Mattermost Mattermost≤ 10.11.0 ≤10.11.10enisa_euvdEU
Mattermost Mattermost≤ 11.2.0 ≤11.2.2enisa_euvdEU
Mattermost Mattermost≤ 11.3.0 ≤11.3.1enisa_euvdEU
Mattermost Mattermost≤ 11.4.0 ≤11.4.0enisa_euvdEU
mattermost mattermost server10.11.0 → 10.11.11nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.2.0 → 11.2.3nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.3.0 → 11.3.2nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server= 11.4.0nvdUScpe:2.3:a: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+incompatible → 11.2.3+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server11.3.0-rc1+incompatible → 11.3.2+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server11.4.0-rc1+incompatible → 11.4.1+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/v810.11.0-rc1 → 10.11.11osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v811.2.0-rc1 → 11.2.3osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v811.3.0-rc1 → 11.3.2osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v811.4.0-rc1 → 11.4.1osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v88.0.0-20260105080200-d27a2195068d → 8.0.0-20260217110922-b7d4a1f1f59bosvUSpkg:golang/github.com/mattermost/mattermost/server/v8

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-3439-vqgj-2gcfMattermost allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences2026-03-26ghsa · osvUS
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to sanitize user-controlled post content in the mmctl commands terminal output which allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences that enable screen manipulation, fake prompts, and clipboard hijacking. Mattermost Advisory ID: MMSA-2026-00599.
GO-2026-5067Mattermost allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences in github.com/mattermost/mattermost-server2026-06-25vendor · osvUS
Mattermost allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape sequences in github.com/mattermost/mattermost-server

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2026-03-26modified 2026-06-17

references (3)

External citations — patches, advisories, analysis.

scry

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