What is the CVSS score of CVE-2025-64763?

CVE-2025-64763 has a CVSS 3.1 base score of 3.7 (Low). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.0%.

Which versions of Debian are affected by CVE-2025-64763?

CVE-2025-64763 is a low-severity vulnerability in Envoy (CVSS 3.7). The limited severity suggests constrained impact, typically requiring specific conditions or local access for exploitation.. A patch is available.

How to fix or mitigate CVE-2025-64763?

During next maintenance window: Apply vendor patches when convenient. Vendor patch is available.

Debian CVE-2025-64763

EUVD-2025-201099 LOW

Protection Mechanism Failure (CWE-693)

2025-12-03 security-advisories@github.com

GHSA-rj35-4m94-77jh

Information Disclosure Debian

3.7

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

3.7 LOW

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Lifecycle Timeline

EUVD ID Assigned

Mar 15, 2026 - 16:14 euvd

EUVD-2025-201099

Analysis Generated

Mar 15, 2026 - 16:14 vuln.today

Patch released

Mar 15, 2026 - 16:14 nvd

Patch available

CVE Published

Dec 03, 2025 - 18:15 nvd

LOW 3.7

DescriptionGitHub Advisory

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.