CVE-2025-27936

Webhook Secret Exposure via Timing attack in MSteams plugin

CVSS 3.1 5.3 MEDIUMEUVD CVSS 3.1 5.3 CVSS 3.1 · [email protected] · Secondary 5.3 MEDIUMCVSS 3.1 · [email protected] · Primary 5.9 MEDIUMCVSS_V3 Publisher rating MODERATEFixed by github.com/mattermost/mattermost/server/v8 10.5.2 Fixed by github.com/mattermost/mattermost/server/v8 8.0.0-20250314142426-c049748b8863 Fixed by github.com/mattermost/mattermost-plugin-msteams 2.1.0osv · severity unknownFixed by github.com/mattermost/mattermost-server 10.5.2+incompatible Fixed by github.com/mattermost/mattermost/server/v8 8.0.0-20250218121836-2b5275d87136KEV status unknown

Original advisory

cve-program · CVE-2025-27936

Published

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.

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euvd · EUVD-2025-11359

Published

Read the publisher's advisory

nvd · CVE-2025-27936

Published

Read the publisher's advisory

osv · GHSA-2j87-p623-8cc2

Published

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osv · GO-2025-3618

Published

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.

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Affected versions, risk and source history

cve-program · CVE-2025-27936

Published

Mattermost

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "defaultStatus": "unaffected",
                    "product": "Mattermost",
                    "vendor": "Mattermost",
                    "versions": [
                        {
                            "lessThanOrEqual": "10.5.1",
                            "status": "affected",
                            "version": "10.5.0",
                            "versionType": "semver"
                        },
                        {
                            "status": "unaffected",
                            "version": "10.6.0"
                        },
                        {
                            "status": "unaffected",
                            "version": "10.5.2"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON

euvd · EUVD-2025-11359

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Apr 16, 2025, 9:14:55 AM

dateUpdated: Apr 16, 2025, 2:32:45 PM

2 related source bulletins · separate from aliases

openSUSE-SU-2025:15017-1: govulncheck-vulndb-0.0.20250422T181640-1.1 on GA media

CVE-2019-15119 · CVE-2025-1386 · CVE-2025-2424 · CVE-2025-24358 · CVE-2025-2475 · CVE-2025-24839 · CVE-2025-24866 · CVE-2025-2564 · CVE-2025-27538 · CVE-2025-27571 · CVE-2025-27936 · CVE-2025-30206 · CVE-2025-31363 · CVE-2025-32093 · CVE-2025-32431 · CVE-2025-32445 · CVE-2025-32793 · CVE-2025-32963 · CVE-2025-3801 · CVE-2025-43970 · CVE-2025-43971 · CVE-2025-43972 · CVE-2025-43973

WID-SEC-W-2025-0578: Mattermost Plugins: Schwachstelle ermöglicht Offenlegung von Daten

CVE-2025-27936

No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.

Original source record · Cite this exact observation · Complete original publisher JSON

nvd · CVE-2025-27936

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Analyzed

Weakness classifications: CWE-208

Original publisher date fields

published: 2025-04-16T10:15:14.797

lastModified: 2026-06-17T09:04:25.247

2 source CPE criteria · context only

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
cpe:2.3:a:mattermost:ms_teams:*:*:*:*:*:*:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Original source record · Cite this exact observation · Complete original publisher JSON

osv · GHSA-2j87-p623-8cc2

Published

github.com/mattermost/mattermost/server/v8

SEMVER · introduced 10.5.0 → fixed 10.5.2

github.com/mattermost/mattermost/server/v8

SEMVER · introduced 0 → fixed 8.0.0-20250314142426-c049748b8863

github.com/mattermost/mattermost-plugin-msteams

SEMVER · introduced 0 → fixed 2.1.0

Original source record · Cite this exact observation · Complete original publisher JSON

osv · GO-2025-3618

Published

github.com/mattermost/mattermost-plugin-msteams

SEMVER · introduced 0

github.com/mattermost/mattermost-server

SEMVER · introduced 10.5.0+incompatible → fixed 10.5.2+incompatible

github.com/mattermost/mattermost-server/v5

SEMVER · introduced 0

github.com/mattermost/mattermost-server/v6

SEMVER · introduced 0

github.com/mattermost/mattermost/server/v8

SEMVER · introduced 0 → fixed 8.0.0-20250218121836-2b5275d87136

Original source record · Cite this exact observation · Complete original publisher JSON