GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. In version 4.3.0, a remote Denial of Service (DoS) vulnerability exists in GoBGP due to a nil pointer dereference. When a malformed BGP UPDATE message contains an unrecognized Path Attribute marked as "Well-known," the daemon fails to interrupt the message handling flow. This results in an illegal memory access and a full process crash (panic). This issue has been patched in version 4.4.0.