6.5

CVE-2025-64527: envoyproxy envoy NULL Pointer Dereference

CVSS: 6.5v3.1MediumAnalyzed
AliasesGHSA-mp85-7mrq-r866BIT-envoy-2025-64527
Published 03-12-2025Last modified 03-12-2025
Open JSON

Vulnerability summary

CVE-2025-64527 is a medium (CVSS 6.5) NULL Pointer Dereference vulnerability in envoyproxy envoy. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.7% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.53%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Timeline

  1. 03-12-2025
    PublishedVulnerability first disclosed.
  2. 03-12-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.53%

Chance of exploitation in the next 30 days

Percentile

44%

Versus all other CVEs

30-day change

0.00 pp

From 0.53% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.53%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Envoy

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Envoyproxy1 product
  • envoy≥ 1.36.0, ≤ 1.36.2 | ≥ 1.35.0, ≤ 1.35.6 | ≥ 1.34.0, ≤ 1.34.10 | ≤ 1.33.12 | < 1.33.13 | ≥ 1.34.0, < 1.34.11 | ≥ 1.35.0, < 1.35.7 | ≥ 1.36.0, < 1.36.3
Github.com/envoyproxy1 product
  • envoy≥ 1.36.0, < 1.36.3 | ≥ 1.35.0, < 1.35.7 | ≥ 1.34.0, < 1.34.11 | < 1.33.13

2 vendors · 2 products

References

3 links