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CVE-2025-64527

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CVE-2025-64527

Published: Dec 3, 2025

Modified: Dec 3, 2025

PUBLISHED

CVSS v3.1

6.5

MEDIUM

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.

VendorProductVersions

envoyproxy

envoy

affected
>= 1.36.0, <= 1.36.2
affected
>= 1.35.0, <= 1.35.6
affected
>= 1.34.0, <= 1.34.10
affected
<= 1.33.12

Weaknesses (CWE)

CWE-476

CVSS v3.1 Details

CVSS v3.1 Vector

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

References

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