Erlang OTP public_key vulnerabilities

A resource allocation vulnerability in Erlang/OTP's public_key certificate path validation allows a remote unauthenticated attacker to cause denial of service by sending a crafted X.509 certificate chain during TLS handshake. The certificate policy tree grows without bounds, exhausting BEAM schedulers and node memory, crashing the entire VM. This affects all TLS connections that validate peer certificates by default.

A vulnerability in the Erlang OTP public_key library allows bypassing DNS nameConstraints via subject CommonName fallback in TLS hostname verification. Two flaws enable a subordinate CA with restricted DNS nameConstraints to issue a leaf certificate accepted for an out-of-scope hostname.

A vulnerability in the public_key module (pubkey_cert) of Erlang OTP allows a non-CA certificate (basicConstraints cA:false) to be accepted as an intermediate issuer in a certificate chain. Two flaws in pubkey_cert:validate_extensions/7 cause a missing keyUsage extension to completely bypass the keyCertSign requirement, enabling certificate chain forgery.