GHSA-fgw5-hp8f-xfhc
MEDIUMGHSA-fgw5-hp8f-xfhc is a medium-severity (CVSS 5) vulnerability in istio.io/istio. O3 Security confirms whether GHSA-fgw5-hp8f-xfhc is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Istio: SSRF via RequestAuthentication jwksUri
Real-World Exposure
istio.io/istioReal-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
Impact
When a RequestAuthentication resource is created with a jwksUri pointing to an internal service, istiod makes an unauthenticated HTTP GET request to that URL without filtering out localhost or link local ips. This can result in sensitive data being distributed to Envoy proxies via xDS configuration.
Note: a partial mitigation for this was released in 1.29.1, 128.5, and 1.27.8; however, it was incomplete and missed a few codepaths. 1.29.2 and 1.28.6 contain the more robust fix.
Patches
Has the problem been patched? What versions should users upgrade to?
Workarounds
Users can deploy a ValidatingAdmissionPolicy to prevent the creation of RequestAuthentication resources with suspicious jwksUri field values (e.g. localhost, 127.0.0.0/8, 169.254.0.0/16, the ipv6 variants, etc.).
References
None
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | istio.io/istio | all versions | 0.0.0-20260410004459-189832a289c1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for istio.io/istio. 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 istio.io/istio to 0.0.0-20260410004459-189832a289c1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fgw5-hp8f-xfhc 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-fgw5-hp8f-xfhc 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-fgw5-hp8f-xfhc. 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-fgw5-hp8f-xfhc in your dependencies?
O3 detects GHSA-fgw5-hp8f-xfhc across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.