How severe is GHSA-q22q-2rrf-m27p?

GHSA-q22q-2rrf-m27p has a CVSS score of 8.7/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-q22q-2rrf-m27p?

GHSA-q22q-2rrf-m27p affects the following packages: github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost/server/v8 (Go). Ecosystems affected: Go.

How do I fix GHSA-q22q-2rrf-m27p?

Update github.com/mattermost/mattermost/server/v8 to 9.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q22q-2rrf-m27p is resolved across your whole dependency graph.

How do I detect GHSA-q22q-2rrf-m27p in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-q22q-2rrf-m27p if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is GHSA-q22q-2rrf-m27p actively exploited in the wild?

No public exploit code has been indexed for GHSA-q22q-2rrf-m27p yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-q22q-2rrf-m27p?

GHSA-q22q-2rrf-m27p has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 31th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-q22q-2rrf-m27p?

GHSA-q22q-2rrf-m27p is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-q22q-2rrf-m27p published, and has it been updated?

GHSA-q22q-2rrf-m27p was published on August 1, 2024 and was last updated on November 18, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

Mattermost allows unsolicited invites to expose access to local channelsGHSA-q22q-2rrf-m27p

HIGH

GHSA-q22q-2rrf-m27p is a high-severity (CVSS 8.7) CWE-284 vulnerability in github.com/mattermost/mattermost/server/v8. A fix is available for github.com/mattermost/mattermost/server/v8 — see the affected versions and patch details below.

Also known asCVE-2024-39777GO-2024-3092

Published

Aug 1, 2024

Updated

Nov 18, 2024

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-q22q-2rrf-m27p.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 9.9.0&&< 9.9.1	9.9.1`go get github.com/mattermost/mattermost/server/v8@v9.9.1`
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 9.5.0&&< 9.5.7	9.5.7`go get github.com/mattermost/mattermost/server/v8@v9.5.7`
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 9.7.0&&< 9.7.6	9.7.6`go get github.com/mattermost/mattermost/server/v8@v9.7.6`
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 9.8.0&&< 9.8.1	9.8.1`go get github.com/mattermost/mattermost/server/v8@v9.8.1`

Affected Products

1 product · 4 configurations

Application

mattermostmattermost

≥ 9.8.0 && < 9.8.2

1 version

9.9.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mattermost/mattermost/server/v8 to 9.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q22q-2rrf-m27p is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is GHSA-q22q-2rrf-m27p in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

8.7/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

CWE Classification

CWE-284CWE-284

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

Timeline

Disclosed

Aug 1, 2024

Last updated

Nov 18, 2024

Identifiers

GHSA-q22q-2rrf-m27p

GO-2024-3092

References

Advisorynvd.nist.gov · CVE 2024 39777 Webmattermost.com · security updates Packagegithub.com · mattermost

Related vulnerabilities

This CVE is high severity; 2 of 8 other CVEs affecting v8 are rated as high or higher (top: high).

CVE-2026-8823CVE-2026-6046CVE-2026-7387CVE-2026-6961CVE-2026-7184CVE-2026-6689CVE-2026-6739CVE-2026-3433

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedNov 18, 2024

Mattermost allows unsolicited invites to expose access to local channelsGHSA-q22q-2rrf-m27p

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is GHSA-q22q-2rrf-m27p in your dependencies?