CVE-2025-62690 is a low-severity (CVSS 3.1) Open Redirect 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.
Open redirect in error page when link opened in new tab
Exploitation Status
No confirmed exploitation observed yet
- 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 CVE-2025-62690.
EPSS Exploitation Probability
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
github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost🐹github.com/mattermost/mattermostReal-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 10.11.x <= 10.11.4 fail to validate redirect URLs on the /error page, which allows an attacker to redirect a victim to a malicious site via a crafted link opened in a new tab.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 8.0.0-20250721062209-4952acea88ce&&< 8.0.0-20251016131338-dad6bd7a1509 | 8.0.0-20251016131338-dad6bd7a1509go get github.com/mattermost/mattermost/server/v8@v8.0.0-20251016131338-dad6bd7a1509 |
| 🐹Go | github.com/mattermost/mattermost | ≥ 10.11.0-rc1&&< 10.11.5-0.20251016131338-dad6bd7a1509 | 10.11.5-0.20251016131338-dad6bd7a1509go get github.com/mattermost/mattermost@v10.11.5-0.20251016131338-dad6bd7a1509 |
| 🐹Go | github.com/mattermost/mattermost | ≥ 11.0.0-alpha.1&&< 11.1.0 | 11.1.0go get github.com/mattermost/mattermost@v11.1.0 |
Affected Products
mattermost servermattermostDetection & mitigation playbook
Open-source dependencyDetect
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 8.0.0-20251016131338-dad6bd7a1509 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-62690 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Frequently Asked Questions
Is CVE-2025-62690 in your dependencies?
Find it across Go, including transitive dependencies.