Vulnerability in Envoyproxy Envoy

CVE-2025-46821

Envoy is a cloud-native edge/middle/service proxy. Prior to versions 1.34.1, 1.33.3, 1.32.6, and 1.31.8, Envoy's URI template matcher incorrectly excludes the `*` character from a set of valid characters in the URI path. As a result URI path containing the `*` character will not match a URI template expressions. This can result in bypass of RBAC rules when configured using the `uri_template` permissions. This vulnerability is fixed in Envoy versions v1.34.1, v1.33.3, v1.32.6, v1.31.8. As a workaround, configure additional RBAC permissions using `url_path` with `safe_regex` expression.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (16.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-46821: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

  • Envoyproxy Envoy — versions < 1.31.8, >= 1.34.0, < 1.34.1, >= 1.33.0, < 1.33.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-46821?
CVE-2025-46821 is a medium-severity vulnerability in Envoyproxy Envoy, classified under Overly Restrictive Regular Expression. CVSS score: 5.3/10. Published 2025-05-07.
How severe is CVE-2025-46821?
Medium severity. CVSS v3 base score is 5.3 out of 10.