What is CVE-2022-23635?

CVE-2022-23635 is a high-severity vulnerability in Istio, classified under Improper Authentication. CVSS score: 7.5/10. Published 2022-02-22.

How severe is CVE-2022-23635?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2022-23635 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Istio

CVE-2022-23635

Istio is an open platform to connect, manage, and secure microservices. In affected versions the Istio control plane, `istiod`, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted message which results in the control plane crashing. This endpoint is served over TLS port 15012, but does not require any authentication from the attacker. For simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially [multicluster](https://istio.io/latest/docs/setup/install/multicluster/primary-remote/) topologies, this port is exposed over the public internet. There are no effective workarounds, beyond upgrading. Limiting network access to Istiod to the minimal set of clients can help lessen the scope of the vulnerability to some extent.

Vulnerability class: Broken Authentication

Published 2022-02-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.017 (75.8th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 75.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000

Affected products

Istio — versions >= 1.13.0, < 1.13.1, >= 1.12.0, < 1.12.4, < 1.11.7

Weakness classification (CWE)

Public proof-of-concept exploits

References

github.com/istio/istio/security/advisories/GHSA-856q-xv3c-7f2f (Third Party Advisory, Issue Tracking)
github.com/istio/istio/commit/5f3b5ed958ae75156f8656fe7b3794f78e94db84 (Patch, Third Party Advisory)
istio.io/latest/news/security/istio-security-2022-003 (Third Party Advisory)

Frequently asked questions

What is CVE-2022-23635?: CVE-2022-23635 is a high-severity vulnerability in Istio, classified under Improper Authentication. CVSS score: 7.5/10. Published 2022-02-22.
How severe is CVE-2022-23635?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2022-23635 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.