EnvoyApplication · Envoyproxy

CVE-2025-46821

MEDIUM · 5.3 CVSS v3.1 Published 2025-05-07
Fix available
A fix is available. Upgrade to 1.31.8 / 1.32.6 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Envoy's URI template matcher incorrectly excludes the `*` character from valid URI path characters, causing paths containing `*` to fail matching against uri_template permissions. This allows requests with `*` in the path to bypass RBAC rules configured using uri_template permissions.

MitigationUpgrade Envoy to version 1.34.1, 1.33.3, 1.32.6, or 1.31.8 and later. Alternatively, configure additional RBAC permissions using `url_path` with `safe_regex` as a workaround until upgrade is possible.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
EnvoyApplication
Affected:< 1.31.8>= 1.32.0, < 1.32.6>= 1.33.0, < 1.33.3= 1.34.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Envoy version
    Run `envoy --version` or look at the Envoy container image tag / binary metadata to identify the exact version number
    Affected if The version is < 1.31.8, >= 1.32.0 and < 1.32.6, >= 1.33.0 and < 1.33.3, or exactly 1.34.0
  2. Identify RBAC configuration using uri_template
    Review Envoy configuration files (static or dynamic) and search for RBAC filters with `uri_template` permission type in the matcher rules
    Affected if RBAC is configured with `uri_template` permissions that define path matching rules
  3. Inspect uri_template patterns for path matching
    Examine the uri_template patterns defined in the RBAC permissions - look for any path templates that would match requests containing `*` characters in the URL path
    Affected if The uri_template patterns could match paths that include the `*` character and the Envoy version is affected
  4. Verify if requests with `*` in path bypass RBAC
    If RBAC with uri_template is in use, test sending requests with `*` in the URL path to confirm whether the RBAC policy is being applied correctly
    Affected if Requests with `*` in the path are not being matched by the uri_template RBAC rules when they should be

You are affected if your Envoy version is in the affected range AND you have RBAC policies using uri_template permissions that should match paths containing the `*` character.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.31.8 / 1.32.6 / 1.33.3 or later
Fixed in 1.31.81.32.61.33.3
Interim mitigation

Upgrade Envoy to version 1.34.1, 1.33.3, 1.32.6, or 1.31.8 and later. Alternatively, configure additional RBAC permissions using `url_path` with `safe_regex` as a workaround until upgrade is possible.

Recommended fix High confidence

v1.34.1 (latest stable fixed release)

  1. Upgrade Envoy to one of the fixed versions: v1.34.1, v1.33.3, v1.32.6, or v1.31.8 depending on your current version branch
  2. If upgrade is not immediately possible, implement the workaround: add additional RBAC permissions using `url_path` with `safe_regex` expression to catch URI paths containing the `*` character
  3. After upgrading or applying the workaround, verify that RBAC policies with `uri_template` permissions correctly match paths containing `*` characters

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Envoy Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-46821 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-46821 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data