GHSA-cg3q-j54f-5p7p
HIGHUncontrolled Resource Consumption in promhttp
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
github.com/prometheus/client_golangReal-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
This is the Go client library for Prometheus. It has two separate parts, one for instrumenting application code, and one for creating clients that talk to the Prometheus HTTP API. client_golang is the instrumentation library for Go applications in Prometheus, and the promhttp package in client_golang provides tooling around HTTP servers and clients.
Impact
HTTP server susceptible to a Denial of Service through unbounded cardinality, and potential memory exhaustion, when handling requests with non-standard HTTP methods.
Affected Configuration
In order to be affected, an instrumented software must
- Use any of
promhttp.InstrumentHandler*middleware exceptRequestsInFlight. - Do not filter any specific methods (e.g GET) before middleware.
- Pass metric with
methodlabel name to our middleware. - Not have any firewall/LB/proxy that filters away requests with unknown
method.
Patches
- https://github.com/prometheus/client_golang/pull/962
- https://github.com/prometheus/client_golang/pull/987
Workarounds
If you cannot upgrade to v1.11.1 or above, in order to stop being affected you can:
- Remove
methodlabel name from counter/gauge you use in the InstrumentHandler. - Turn off affected promhttp handlers.
- Add custom middleware before promhttp handler that will sanitize the request method given by Go http.Request.
- Use a reverse proxy or web application firewall, configured to only allow a limited set of methods.
For more information
If you have any questions or comments about this advisory:
- Open an issue in https://github.com/prometheus/client_golang
- Email us at
[email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/prometheus/client_golang | all versions | 1.11.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/prometheus/client_golang. 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 github.com/prometheus/client_golang to 1.11.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cg3q-j54f-5p7p 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 GHSA-cg3q-j54f-5p7p 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 GHSA-cg3q-j54f-5p7p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-cg3q-j54f-5p7p in your dependencies?
O3 detects GHSA-cg3q-j54f-5p7p across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.