CVE-2026-31837 Istio JWKS resolver to prevent private key material from being exposed when JWKS fetch fails.
Istio users face exposure of hardcoded private key material when JWKS fetches fail, requiring an upgrade to secure service mesh authentication.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31837?
CVE-2026-31837 is a high-severity vulnerability in istio, published on 10 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Istio is an open platform to connect, manage, and secure microservices. Prior to 1.29.1, 1.28.5, and 1.27.8, a user of Istio is impacted if the JWKS resolver becomes unavailable or the fetch fails, exposing hardcoded defaults regardless of use of the RequestAuthentication resource. This vulnerability is fixed in 1.29.1, 1.28.5, and 1.27.8.
Which versions are affected by CVE-2026-31837?
It affects 1 product.
Products include Istio Istio.
How do I fix CVE-2026-31837?
Upgrade to a fixed version.
Is CVE-2026-31837 being exploited?
There is no known exploitation of CVE-2026-31837 in the wild and no public exploit code.
Other vulnerabilities in istio
- CVE-2021-31921 Missing authorization in n/a
- CVE-2021-34824 Information disclosure in n/a
- CVE-2021-39155 Authorization Policy Bypass Due to Case Insensitive Host Comparison
- CVE-2021-39156 Fragments in Path May Lead to Authorization Policy Bypass
- CVE-2022-39388 Istio may allow identity impersonation if user has localhost access
Sources
Also known as CLEANSTART-2026-IN05480, GHSA-v75c-crr9-733c, MINI-7wj6-6v2g-rcjr, MINI-82qv-2q2m-c9jp, MINI-86wf-pgj9-g3jj, MINI-87ph-2c98-qjvg and 12 more.