CVE-2023-27591
HIGHUnauthenticated Miniflux user can bypass allowed networks check to obtain Prometheus metrics
EPSS Exploitation Probability
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.
Blast Radius
miniflux.app/v2🐹miniflux.appReal-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
Miniflux is a feed reader. Prior to version 2.0.43, an unauthenticated user can retrieve Prometheus metrics from a publicly reachable Miniflux instance where the METRICS_COLLECTOR configuration option is enabled and METRICS_ALLOWED_NETWORKS is set to 127.0.0.1/8 (the default). A patch is available in Miniflux 2.0.43. As a workaround, set METRICS_COLLECTOR to false (default) or run Miniflux behind a trusted reverse-proxy.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | miniflux.app/v2 | all versions | 2.0.43 |
| 🐹Go | miniflux.app | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for miniflux.app/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update miniflux.app/v2 to 2.0.43 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-27591 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 pinpoints whether CVE-2023-27591 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-27591. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-27591 in your dependencies?
O3 detects CVE-2023-27591 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.