Vulnerability · Published Sep 18, 2026 · Assigned by VulnCheck

CVE-2026-93602rustls-webpki before 0.103.10 CRL Revocation Check Bypass

Medium 4.4

In plain English

A medium-severity security flaw in webpki from rustls. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.4Medium

Exploit odds (30 days)0.2%top 90.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

rustls-webpki versions before 0.103.10 and 0.104.0-alpha.5 contain faulty CRL authority-matching logic that compares only the first distributionPoint against each CRL's IssuingDistributionPoint, ignoring additional distributionPoints. Attackers with a compromised trusted issuing authority can present revoked certificates that pass revocation checks under UnknownStatusPolicy::Allow, or cause incorrect errors under the default deny policy.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:13	rust-rustls-webpki	no fix listed	DEBIAN-CVE-2026-93602
Debian:14	rust-rustls-webpki	0.103.10+ds-1	DEBIAN-CVE-2026-93602
Ubuntu:24.04:LTS	rust-rustls-webpki	no fix listed	UBUNTU-CVE-2026-93602
Ubuntu:26.04:LTS	rust-rustls-webpki	no fix listed	UBUNTU-CVE-2026-93602

Affected products (as reported)

Vendor	Product	Versions
rustls	webpki	0.102.0-alpha.0 – before 0.103.100.104.0-alpha.1 – before 0.104.0-alpha.5

Weakness: CWE-299 · Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N

References

GitHub Security Advisory (GHSA-pwjx-qhcg-rvj4) vendor-advisory
VulnCheck Advisory: rustls-webpki before 0.103.10 CRL Revocation Check Bypass third-party-advisory