CVE-2021-31921

9.8 criticalEPSS 1.5%

Critical (9.8) in istio istio. EPSS 1.5% chance of exploitation in the next 30 days.

Istio before 1.8.6 and 1.9.x before 1.9.5 contains a remotely exploitable vulnerability where an external client can access unexpected services in the cluster, bypassing authorization checks, when a gateway is configured with AUTO_PASSTHROUGH routing configuration.

Severity

CVSS 3.1

9.8 critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 1.5% chance of exploitation in the next 30 days; higher than 73% of CVEs (scores of 2026-11-01)
CWE: CWE-862
Published: 2021-06-02
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

istio:istio

References

https://istio.io/latest/news/security/istio-security-2021-006/
https://istio.io/latest/news/security/istio-security-2021-006/

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