CVE-2026-93602
MediumCVSS 4.4Summary
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.
Risk Assessment
An attacker 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.
Recommendation
Update rustls-webpki to version 0.103.10, 0.104.0-alpha.5, or later. Until patched, consider changing the UnknownStatusPolicy to a more restrictive setting.
Other vulnerabilities in rustls-webpki
See all- CVE-2026-93601Low
rustls-webpki versions >= 0.101.0 and prior to 0.103.12 and 0.104.0-alpha.6 incorrectly accept permitted-subtree DNS name constraints for certificates asserting a wildcard name. For example, a name constraint of accept.example.com is treated as satisfied by a certificate for *.example.com, which could assert reject.example.com outside the permitted subtree.
- CVE-2026-93600Low
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, accepting rather than enforcing them. These constraints apply to otherwise properly issued certificates, so the flaw is reachable after successful signature verification and requires a misissued certificate.
- CVE-2026-93599High
rustls-webpki through 0.103.12 (and 0.104.0-alpha releases before 0.104.0-alpha.7) contains a reachable panic in bit_string_flags() in src/der.rs. The input guard fails to reject a named-bit BIT STRING with content exactly [0x00], causing an underflow and panic. Reachable via BorrowedCertRevocationList::from_der() when a CRL contains an issuingDistributionPoint extension with such an onlySomeReasons value. Requires an application that opts in to CRL revocation checking and parses attacker-influenced CRL bytes; default rustls configuration is unaffected. Fixed in 0.103.13 and 0.104.0-alpha.7.
Original NVD description (English source)
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.