CVE-2024-39777

criticalpriority · track · 38EPSS 0.004 · 30 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.36% (30th) EPSS

CVSS 9.6 · critical

Is it mine?

20 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-27

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels are enabled, which allows a malicious remote to send an invite with the ID of an existing local channel, and that local channel will then become shared without the consent of the local admin.

cvss

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

9.6

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.7–9.6

v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Nprimary · NVD / NIST USexploitability 3.1 · impact 5.8

v3.18.7highCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Nsecondary · ENISA EU

v3.18.7highCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Nsecondary · responsibledisclosure@mattermost.comexploitability 2.3 · impact 5.8

v3.18.7highCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Nsecondary · OSV

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N/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-284USCWE-284US

affected products (20)

Products and version ranges known to be affected.

Mattermost Mattermost Pluginsall versionscert_bundDEcpe:/a:mattermost:mattermost_server:plugins
Mattermost Mattermost≤ 9.9.0enisa_euvdEU
Mattermost Mattermost≤ 9.5.0 ≤9.5.6enisa_euvdEU
Mattermost Mattermost≤ 9.7.0 ≤9.7.5enisa_euvdEU
Mattermost Mattermost≤ 9.8.0 ≤9.8.1enisa_euvdEU
mattermost mattermost9.5.0 → 9.5.7nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
mattermost mattermost9.7.0 → 9.7.6nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
mattermost mattermost9.8.0 → 9.8.2nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
mattermost mattermost= 9.9.0nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-server9.5.0+incompatible → 9.5.7+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server9.7.0+incompatible → 9.7.6+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server9.8.0+incompatible → 9.8.1+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server9.9.0+incompatible → 9.9.1+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/v8all versionsosvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v89.5.0 → 9.5.7osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v89.7.0 → 9.7.6osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v89.8.0 → 9.8.1osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v89.9.0 → 9.9.1osvUSpkg:golang/github.com/mattermost/mattermost/server/v8

advisories (3)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2024-1715Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2024-07-25csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
GHSA-q22q-2rrf-m27pMattermost allows unsolicited invites to expose access to local channels2024-08-01ghsa · osvUS
Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels are enabled, which allows a malicious remote to send an invite with the ID of an existing local channel, and that local channel will then become shared without the consent of the local admin.
GO-2024-3092Mattermost allows unsolicited invites to expose access to local channels in github.com/mattermost/mattermost-server2024-08-30vendor · osvUS
Mattermost allows unsolicited invites to expose access to local channels 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 cert_bund nvd NVD CVE.org MITRE

published 2024-08-01modified 2026-06-17

references (4)

External citations — patches, advisories, analysis.

scry

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