GHSA-82mm-ffjr-h86c is a medium-severity (CVSS 6.8) vulnerability in istio.io/istio. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for istio.io/istio — see the affected versions and patch details below.
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
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
In Istio 1.5.0 though 1.5.8 and Istio 1.6.0 through 1.6.7, when users specify an AuthorizationPolicy resource with DENY actions using wildcard suffixes (e.g. *-some-suffix) for source principals or namespace fields, callers will never be denied access, bypassing the intended policy.
Specific Go Packages Affected
istio.io/istio/pilot/pkg/security/authz/model/matcher
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | istio.io/istio | ≥ 1.5.0&&< 1.5.9 | 1.5.9go get istio.io/istio@v1.5.9 |
| 🐹Go | istio.io/istio | ≥ 1.6.0&&< 1.6.8 | 1.6.8go get istio.io/istio@v1.6.8 |
Affected Products
istioistioResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update istio.io/istio to 1.5.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-82mm-ffjr-h86c 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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
In regards to an AuthorizationPolicy for a TCP service, if using a DENY rule in the source principal (or namespace field) such as: apiVersion: security.istio.io/v1beta1 kind: AuthorizationPolicy ... spec: action: DENY rules: - from: - source: principals: - */ns/servicemesh Consider using an exact or suffix match instead such as: - /foo/bar/ns/servicemeshSource: Red Hat security advisory for GHSA-82mm-ffjr-h86c (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| OpenShift Service Mesh 1.1 | servicemesh-0:1.1.7-1.el8 | RHSA-2020:3425 |
Frequently Asked Questions
Is GHSA-82mm-ffjr-h86c in your dependencies?
Find it across Go, including transitive dependencies.