The security update released in DSA-2850-1 for libyaml introduced a regression in libyaml failing to parse a subset of valid yaml documents. For reference the original advisory text follows. Florian Weimer of the Red Hat Product Security Team discovered a heap-based buffer overflow flaw in LibYAML, a fast YAML 1.1 parser and emitter library. A remote attacker could provide a YAML document with a specially-crafted tag that, when parsed by an application using libyaml, would cause the application to crash or, potentially, execute arbitrary code with the privileges of the user running the application.