CVE-2026-4858

criticalpriority · track · 40EPSS 0.003 · 26 %ileDEEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.33% (26th) EPSS

CVSS 9.9 · critical

Is it mine?

30 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640

cvss

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

9.9

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8–9.9

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.1 · impact 6

v3.19.9criticalAV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

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

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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-22USCWE-22USCWE-22US

affected products (30)

Products and version ranges known to be affected.

Mattermost Mattermost <10.11.15all versionscert_bundDE
Mattermost Mattermost <11.4.5all versionscert_bundDE
Mattermost Mattermost <11.5.4all versionscert_bundDE
Mattermost Mattermost <11.6.1all versionscert_bundDE
Mattermost Mattermost <11.7.0all versionscert_bundDE
Mattermost Mattermost< 10.11.15cert_bundDE
Mattermost Mattermost< 11.4.5cert_bundDE
Mattermost Mattermost< 11.5.4cert_bundDE
Mattermost Mattermost< 11.6.1cert_bundDE
Mattermost Mattermost< 11.7.0cert_bundDE
Mattermost Mattermost≤ 11.4.0 ≤11.4.4enisa_euvdEU
Mattermost Mattermost≤ 11.5.0 ≤11.5.3enisa_euvdEU
Mattermost Mattermost≤ 10.11.0 ≤10.11.14enisa_euvdEU
Mattermost Mattermost≤ 11.6.0 ≤11.6.0enisa_euvdEU
Mattermost Inc Mattermost≤ 11.6.0fstec_bduRU
Mattermost Inc Mattermost10.11.0 → 10.11.14fstec_bduRU
Mattermost Inc Mattermost11.4.0 → 11.4.4fstec_bduRU
Mattermost Inc Mattermost11.5.0 → 11.5.3fstec_bduRU
mattermost mattermost server10.11.0 → 10.11.15nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server11.4.0 → 11.4.5nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

showing 20 of 30

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1173Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2026-04-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
GHSA-c4r7-j7pp-r8mpMattermost has a Path Traversal issue2026-05-21ghsa · osvUS
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL. Mattermost Advisory ID: MMSA-2026-00640.
GO-2026-5311Mattermost has a Path Traversal issue in github.com/mattermost/mattermost-server2026-06-25vendor · osvUS
Mattermost has a Path Traversal issue in github.com/mattermost/mattermost-server

also known as (7)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv cert_bund nvd NVD CVE.org MITRE

published 2026-05-21modified 2026-07-23

references (4)

External citations — patches, advisories, analysis.

scry

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