CVE-2026-41413

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

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.

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-41413 has a CVSS score of 5.0 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260410004459-189832a289c1); upgrading removes the vulnerable code path.

Kodem intelligence

Has the problem been patched? What versions should users upgrade to?

1. What is CVE-2026-41413? CVE-2026-41413 is a medium-severity server-side request forgery (SSRF) vulnerability in istio.io/istio (go), affecting versions < 0.0.0-20260410004459-189832a289c1. It is fixed in 0.0.0-20260410004459-189832a289c1. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-41413? CVE-2026-41413 has a CVSS score of 5.0 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of istio.io/istio are affected by CVE-2026-41413? istio.io/istio (go) versions < 0.0.0-20260410004459-189832a289c1 is affected.
4. Is there a fix for CVE-2026-41413? Yes. CVE-2026-41413 is fixed in 0.0.0-20260410004459-189832a289c1. Upgrade to this version or later.
5. Is CVE-2026-41413 exploitable, and should I be worried? Whether CVE-2026-41413 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-41413 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-41413? Upgrade istio.io/istio to 0.0.0-20260410004459-189832a289c1 or later.