GHSA-hqxw-mm44-gc4r
HIGHIstio Fragments in Path May Lead to Authorization Policy Bypass
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
istio.io/istio🐹istio.io/istio🐹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
Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with #fragment in the path may bypass Istio’s URI path based authorization policies.
Patches
- Istio 1.11.1 and above
- Istio 1.10.4 and above
- Istio 1.9.8 and above
Workarounds
A Lua filter may be written to normalize the path. This is similar to the Path normalization presented in the Security Best Practices guide.
References
More details can be found in the Istio Security Bulletin
For more information
If you have any questions or comments about this advisory, please email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | istio.io/istio | all versions | 1.9.8 |
| 🐹Go | istio.io/istio | ≥ 1.10.0&&< 1.10.4 | 1.10.4 |
| 🐹Go | istio.io/istio | ≥ 1.11.0&&< 1.11.1 | 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 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 1.9.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hqxw-mm44-gc4r 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-hqxw-mm44-gc4r 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-hqxw-mm44-gc4r. 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-hqxw-mm44-gc4r in your dependencies?
O3 detects GHSA-hqxw-mm44-gc4r across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.