{"id":"AZL-103469","summary":"CVE-2026-93599 affecting package kata-containers-cc 3.15.0.aks0-21","details":"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 whose content is exactly [0x00] (zero padding bits and no data bytes), so raw_bits.len() - 1 underflows on the empty slice and the subsequent index operation panics (subtract-with-overflow in debug, index-out-of-bounds in release). The condition is reachable through the public API BorrowedCertRevocationList::from_der() when a CRL contains an issuingDistributionPoint extension with such an onlySomeReasons value. Exploitation requires an application that explicitly opts in to CRL revocation checking by passing RevocationOptions to verify_for_usage() and that parses CRL bytes obtained from a source the attacker can influence; the default rustls configuration, which does not use RevocationOptions, is unaffected. A crafted CRL causes a denial of service via the panic. Fixed in 0.103.13 and 0.104.0-alpha.7.","modified":"2026-09-25T14:16:07.646781833Z","published":"2026-09-18T14:19:11Z","upstream":["CVE-2026-93599"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93599"}],"affected":[{"package":{"name":"kata-containers-cc","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kata-containers-cc"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.15.0.aks0-21"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-103469.json"}}],"schema_version":"1.9.0"}