2.2

CVE-2026-93600: rustls webpki Improper Certificate Validation

CVSS: 2.2v3.1LowAwaiting analysis
AliasesUBUNTU-CVE-2026-93600DEBIAN-CVE-2026-93600GHSA-965h-392x-2mh5
Published 18-09-2026Last modified 21-09-2026
Open JSON

Vulnerability summary

CVE-2026-93600 is a low (CVSS 2.2) Improper Certificate Validation vulnerability in rustls webpki. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.3% of scored vulnerabilities.

Overall risk
9/100
0100
Minimal · default modelHow is this calculated?
CVSS score
2.2/10
010
Low · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 6 · Related 6
OPENSUSE-RU-2026:22132-1OPENSUSE-SU-2026:11936-1OPENSUSE-SU-2026:21982-1OPENSUSE-SU-2026:22016-1SUSE-SU-2026:23983-1SUSE-SU-2026:24014-1

Timeline

  1. 18-09-2026
    PublishedVulnerability first disclosed.
  2. 21-09-2026
    Last modifiedVulnerability information updated.

Description

rustls-webpki (rustls/webpki) versions 0.101.0 through 0.103.11 and 0.104.0-alpha releases before 0.104.0-alpha.6 ignore X.509 name constraints that apply to URI names, causing such constraints to be accepted rather than enforced. Because name constraints are restrictions on otherwise properly issued certificates, the flaw is only reachable after successful signature verification and requires a misissued certificate to exploit; the library also provides no API for asserting URI names, and URI name constraints are otherwise unimplemented. Versions 0.103.12 and 0.104.0-alpha.6 reject URI name constraints unconditionally.

CVSS metrics

8 scores · 5 sources · 2 versions

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

0.00 pp

From 0.18% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.18%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Crates.Io1 product
  • rustls-webpki≥ 0.101.0, < 0.103.12 | ≥ 0.104.0-alpha.1, < 0.104.0-alpha.6
Debian1 product
  • rust-rustls-webpkiAll versions (No fix recorded) | < 0.103.13+ds-1
Rustls1 product
  • webpki≥ 0.101.0, < 0.103.12 | ≥ 0.104.0-alpha.1, < 0.104.0-alpha.6
Ubuntu1 product
  • rust-rustls-webpkiAll versions (No fix recorded)

4 vendors · 4 products

References

8 links