TI-2025-39917 Aliases CVE-2025-64527 GHSA-mp85-7mrq-r866

Envoy crashes when JWT authentication is configured with the remote JWKS fetching

LOW 30CWE-476Published 2025-12-03 · Updated 2025-12-03

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-476.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00564 47th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial github.com/envoyproxy/envoy (Go): 1.36.3, 1.35.7, 1.34.11 +1Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
envoyproxy	envoy	1.36.0 – 1.36.2; 1.35.0 – 1.35.6; 1.34.0 – 1.34.10; up to 1.33.12	—	No fix listed	CNA
—	github.com/envoyproxy/envoy (Go)	1.36.0 to before 1.36.3	1.36.3	Patch available	GHSA-mp85-7mrq-r866
—	github.com/envoyproxy/envoy (Go)	1.35.0 to before 1.35.7	1.35.7	Patch available	GHSA-mp85-7mrq-r866
—	github.com/envoyproxy/envoy (Go)	1.34.0 to before 1.34.11	1.34.11	Patch available	GHSA-mp85-7mrq-r866
—	github.com/envoyproxy/envoy (Go)	before 1.33.13	1.33.13	Patch available	GHSA-mp85-7mrq-r866

envoy Vendorenvoyproxy Affected 1.36.0 – 1.36.2; 1.35.0 – 1.35.6; 1.34.0 – 1.34.10; up to 1.33.12 Fixed in — No fix listed CNA
github.com/envoyproxy/envoy (Go) Vendor— Affected 1.36.0 to before 1.36.3 Fixed in 1.36.3 Patch available GHSA-mp85-7mrq-r866
github.com/envoyproxy/envoy (Go) Vendor— Affected 1.35.0 to before 1.35.7 Fixed in 1.35.7 Patch available GHSA-mp85-7mrq-r866
github.com/envoyproxy/envoy (Go) Vendor— Affected 1.34.0 to before 1.34.11 Fixed in 1.34.11 Patch available GHSA-mp85-7mrq-r866
github.com/envoyproxy/envoy (Go) Vendor— Affected before 1.33.13 Fixed in 1.33.13 Patch available GHSA-mp85-7mrq-r866

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:envoyproxy:envoy::::::::	before 1.33.13; 1.34.0 to before 1.34.11; 1.35.0 to before 1.35.7; 1.36.0 to before 1.36.3	Vulnerable	envoyproxy

cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* Versions before 1.33.13; 1.34.0 to before 1.34.11; 1.35.0 to before 1.35.7; 1.36.0 to before 1.36.3 Vulnerable ·envoyproxy

Remediation

Fix · GHSA-mp85-7mrq-r866 github.com/envoyproxy/envoy (Go) Fixed in 1.36.3 Advisory →
Fix · GHSA-mp85-7mrq-r866 github.com/envoyproxy/envoy (Go) Fixed in 1.35.7 Advisory →
Fix · GHSA-mp85-7mrq-r866 github.com/envoyproxy/envoy (Go) Fixed in 1.34.11 Advisory →
Fix · GHSA-mp85-7mrq-r866 github.com/envoyproxy/envoy (Go) Fixed in 1.33.13 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
OpenShift Service Mesh 2	Affected	No fix yet: Fix deferred
OpenShift Service Mesh 3	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2025-64527
2026-10-03 Alias added: GHSA-mp85-7mrq-r866

References

TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
TI-2024-20001 HTTP/2: CPU exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
TI-2024-18524 HTTP/2: memory exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
TI-2023-12215 Envoy client may fake the header `x-envoy-original-path` CVSS 3.1CRITICAL 9.1
TI-2023-18002 Envoy vulnerable to OAuth2 credentials exploit with permanent validity CVSS 3.1CRITICAL 9.8

See all 126 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences