Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, Envoy crashes when JWT authentication is configured with the remote JWKS fetching, allow_missing_or_failed is enabled, multiple JWT tokens are present in the request headers and the JWKS fetch fails. This is caused by a re-entry bug in the JwksFetcherImpl. When the first token's JWKS fetch fails, onJwksError() callback triggers processing of the second token, which calls fetch() again on the same fetcher object. The original callback's reset() then clears the second fetch's state (receiver_ and request_) which causes a crash when the async HTTP response arrives.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mp85-7mrq-r866 Envoy crashes when JWT authentication is configured with the remote JWKS fetching
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 06 Dec 2025 02:00:00 +0900

Type Values Removed Values Added
CPEs cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*

Fri, 05 Dec 2025 01:45:00 +0900

Type Values Removed Values Added
First Time appeared Envoyproxy
Envoyproxy envoy
Vendors & Products Envoyproxy
Envoyproxy envoy

Thu, 04 Dec 2025 21:15:00 +0900

Type Values Removed Values Added
Weaknesses CWE-248
References
Metrics threat_severity

None

threat_severity

Moderate


Thu, 04 Dec 2025 06:15:00 +0900

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 04 Dec 2025 03:15:00 +0900

Type Values Removed Values Added
Description Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, Envoy crashes when JWT authentication is configured with the remote JWKS fetching, allow_missing_or_failed is enabled, multiple JWT tokens are present in the request headers and the JWKS fetch fails. This is caused by a re-entry bug in the JwksFetcherImpl. When the first token's JWKS fetch fails, onJwksError() callback triggers processing of the second token, which calls fetch() again on the same fetcher object. The original callback's reset() then clears the second fetch's state (receiver_ and request_) which causes a crash when the async HTTP response arrives.
Title Envoy crashes when JWT authentication is configured with the remote JWKS fetching
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-12-03T20:18:19.588Z

Reserved: 2025-11-05T21:15:39.401Z

Link: CVE-2025-64527

cve-icon Vulnrichment

Updated: 2025-12-03T20:18:15.687Z

cve-icon NVD

Status : Analyzed

Published: 2025-12-03T18:15:46.863

Modified: 2025-12-05T16:56:40.850

Link: CVE-2025-64527

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-12-03T12:00:00Z

Links: CVE-2025-64527 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-12-05T01:43:56Z

Weaknesses