How severe is GHSA-876j-jfqf-m7j7?

No CVSS score has been assigned to GHSA-876j-jfqf-m7j7 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-876j-jfqf-m7j7?

GHSA-876j-jfqf-m7j7 affects the following packages: github.com/mattermost/mattermost-server (Go), github.com/mattermost/mattermost-server (Go), github.com/mattermost/mattermost-server (Go). Ecosystems affected: Go.

How do I fix GHSA-876j-jfqf-m7j7?

Update github.com/mattermost/mattermost-server to 4.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-876j-jfqf-m7j7 is resolved across your whole dependency graph.

How do I detect GHSA-876j-jfqf-m7j7 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-876j-jfqf-m7j7 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-876j-jfqf-m7j7?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-876j-jfqf-m7j7 can be triaged on real exposure rather than presence alone.

Is GHSA-876j-jfqf-m7j7 actively exploited in the wild?

No public exploit code has been indexed for GHSA-876j-jfqf-m7j7 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-876j-jfqf-m7j7?

GHSA-876j-jfqf-m7j7 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 55th 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-876j-jfqf-m7j7?

GHSA-876j-jfqf-m7j7 is classified as Improper Privilege Management (CWE-269). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-876j-jfqf-m7j7 published, and has it been updated?

GHSA-876j-jfqf-m7j7 was published on May 24, 2022 and was last updated on December 9, 2025. 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

GHSA-876j-jfqf-m7j7 — mattermost-server

GHSA-876j-jfqf-m7j7 is a Improper Privilege Management vulnerability in github.com/mattermost/mattermost-server. A fix is available for github.com/mattermost/mattermost-server — see the affected versions and patch details below.

Mattermost Server exposes OAuth personal access tokens to attackers

Also known asCVE-2017-18884GO-2025-4197

Published

May 24, 2022

Updated

Dec 9, 2025

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs55th percentile — riskier than 55% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

3 pkgs affected

🐹github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-server

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

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows attackers to gain privileges by using a registered OAuth application with personal access tokens.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/mattermost/mattermost-server`	all versions	4.1.2`go get github.com/mattermost/mattermost-server@v4.1.2`
🐹Go	`github.com/mattermost/mattermost-server`	≥ 4.2.0-rc1&&< 4.2.1	4.2.1`go get github.com/mattermost/mattermost-server@v4.2.1`
🐹Go	`github.com/mattermost/mattermost-server`	≥ 4.3.0-rc1&&< 4.3.0	4.3.0`go get github.com/mattermost/mattermost-server@v4.3.0`

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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mattermost/mattermost-server to 4.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-876j-jfqf-m7j7 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-876j-jfqf-m7j7 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-876j-jfqf-m7j7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows attackers to gain privileges by using a registered OAuth application with personal access tokens.

O3 Security · Impact-Aware SCA

Is GHSA-876j-jfqf-m7j7 in your dependencies?

O3 Security finds GHSA-876j-jfqf-m7j7 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works