CVE-2026-65634

Name of the Vulnerable Software and Affected Versions Erlang/OTP versions 17.0 through 27.3.4.17 Erlang/OTP versions 28.0 through 28.5.0.6 Erlang/OTP versions 29.0 through 29.1.0

Description Inefficient algorithmic complexity in the asn1 OBJECT IDENTIFIER decoder allows a remote unauthenticated attacker to cause a denial of service by sending a crafted OID during the TLS handshake. The issue occurs because the decoder accumulates a base-128 subidentifier into an unbounded integer, resulting in quadratic total work relative to the size of a single subidentifier. This behavior is present in the asn1rtt ber:dec subidentifiers/3 function within lib/asn1/src/asn1rtt ber.erl, the asn1rtt per common:dec subidentifiers/3 function in lib/asn1/src/asn1rtt per common.erl, and the asn1rtt jer:json2oid/1 function in lib/asn1/src/asn1rtt jer.erl. The vulnerable decoder is used in every ASN.1 module containing an OBJECT IDENTIFIER, including OTP-PUB-KEY during X.509 certificate parsing via public key:pkix decode cert/2. Since this process occurs before signature or trust chain verification, any Erlang service parsing peer TLS certificates, such as TLS clients or mutual-TLS servers, is exposed.

Recommendations Update Erlang/OTP to version 27.3.4.18 or later. Update Erlang/OTP to version 28.5.0.7 or later. Update Erlang/OTP to version 29.1.1 or later.