7.1

CVE-2025-66220: envoyproxy envoy Improper Null Termination

CVSS: 7.1v3.1HighAnalyzed
AliasesGHSA-rwjg-c3h2-f57pBIT-envoy-2025-66220
Published 03-12-2025Last modified 03-12-2025
Open JSON

Vulnerability summary

CVE-2025-66220 is a high (CVSS 7.1) Improper Null Termination vulnerability in envoyproxy envoy. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.7% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
38/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.1/10
010
High · v3.1 (NVD)
EPSS score
0.17%
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’s mTLS certificate matcher for match_typed_subject_alt_names may incorrectly treat certificates containing an embedded null byte (\0) inside an OTHERNAME SAN value as valid matches.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

0.00 pp

From 0.17% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.17%

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