CVE-2026-93602: rustls-webpki before 0.103.10 CRL Revocation Check Bypass
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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
rustls-webpkito a version that resolves this vulnerability.Fixed in 0.103.10 - Upgrade
Upgrade
rustls-webpkito a version that resolves this vulnerability.Fixed in 0.104.0-alpha.5 - Compensating control
Ensure revocation checking is not configured to allow unknown certificate status (e.g., avoid UnknownStatusPolicy::Allow) when using rustls-webpki.
Event History
Frequently Asked Questions
Who is realistically exposed to a revocation-check bypass?
Applications using affected rustls-webpki versions and CRL revocation checking with UnknownStatusPolicy::Allow are exposed if an attacker has compromised a trusted issuing authority. The attacker could then present a revoked certificate that passes revocation checks.
Is the default revocation policy vulnerable to the same bypass?
The described bypass applies under UnknownStatusPolicy::Allow. Under the default deny policy, the faulty authority-matching logic can instead produce incorrect errors.
What versions contain the faulty CRL authority-matching logic?
Affected versions are rustls-webpki releases before 0.103.10 and before 0.104.0-alpha.5.