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 Erlang OTP public_key library (pubkey_cert module) allows improper following of a certificate's chain of trust. A non-CA certificate with basicConstraints cA:false and no keyUsage extension is incorrectly accepted as an intermediate issuer, enabling certificate chain forgery. Affected OTP versions: 17.0 through 29.0.1, 28.5.0.1, 27.3.4.12, and 26.2.5.21.