What is CVE-2021-34824?

CVE-2021-34824 is a high-severity vulnerability in Istio. CVSS score: 8.8/10. Published 2021-06-29.

How severe is CVE-2021-34824?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-34824 known to be exploited?

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

Vulnerability in Istio

CVE-2021-34824

Istio (1.8.x, 1.9.0-1.9.5 and 1.10.0-1.10.1) contains a remotely exploitable vulnerability where credentials specified in the Gateway and DestinationRule credentialName field can be accessed from different namespaces.

Published 2021-06-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.020 (79.8th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 79.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.020 · newest: 0.020 · change: +0.000

Affected products

Istio

Public proof-of-concept exploits

rsalmond/CVE-2021-34824

References

github.com/istio/istio/releases (Third Party Advisory, Release Notes)
istio.io/latest/news/security/istio-security-2021-007 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-34824?: CVE-2021-34824 is a high-severity vulnerability in Istio. CVSS score: 8.8/10. Published 2021-06-29.
How severe is CVE-2021-34824?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-34824 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.