CVE-2025-27936

mediumpriority · track · 24EPSS 0.003 · 28 %ileDEEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.34% (28th) EPSS

CVSS 5.9 · medium

Is it mine?

16 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-27

Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.

cvss

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

5.9

010

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

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 2.2 · impact 3.6

v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · ENISA EU

v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 1.6 · impact 3.6

v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · OSV

v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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-208USCWE-208US

affected products (16)

Products and version ranges known to be affected.

Mattermost Mattermost <10.5.2all versionscert_bundDE
Mattermost Mattermost Plugin MSTeams <2.1.0all versionscert_bundDE
Mattermost Mattermost≤ Plugin MSTeams <2.1.0cert_bundDE
Mattermost Mattermost< 10.5.2cert_bundDE
Mattermost Mattermost≤ 10.5.0 ≤10.5.1enisa_euvdEU
Mattermost Mattermostall versionsenisa_euvdEU
mattermost mattermost server< 10.5.2nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost ms teams< 2.1.0nvdUScpe:2.3:a:mattermost:ms_teams:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-plugin-msteamsall versionsosvUSpkg:golang/github.com/mattermost/mattermost-plugin-msteams
Go github.com/mattermost/mattermost-plugin-msteams< 2.1.0osvUSpkg:golang/github.com/mattermost/mattermost-plugin-msteams
Go github.com/mattermost/mattermost-server10.5.0+incompatible → 10.5.2+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< 8.0.0-20250218121836-2b5275d87136osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v8< 8.0.0-20250314142426-c049748b8863osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v810.5.0 → 10.5.2osvUSpkg:golang/github.com/mattermost/mattermost/server/v8

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2025-0578Mattermost Plugins: Schwachstelle ermöglicht Offenlegung von DatenDeutsch2025-03-17csaf · cert_bundDE
Ein Angreifer kann eine Schwachstelle in Mattermost ausnutzen, um Informationen offenzulegen
GHSA-2j87-p623-8cc2Mattermost vulnerable to Observable Timing Discrepancy2025-04-16ghsa · osvUS
Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.
GO-2025-3618Mattermost vulnerable to Observable Timing Discrepancy in github.com/mattermost/mattermost-plugin-msteams2025-04-22vendor · osvUS
Mattermost vulnerable to Observable Timing Discrepancy in github.com/mattermost/mattermost-plugin-msteams. 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-plugin-msteams before v2.1.0.

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv cert_bund nvd NVD CVE.org MITRE

published 2025-04-16modified 2026-06-17

references (4)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan