An invalid memory access flaw is present in libyang before v1.0-r1 in the function resolvefeaturevalue() when an if-feature statement is used inside a list key node, and the feature used is not defined. Applications that use libyang to parse untrusted input yang files may crash.

A stack consumption issue is present in libyang before v1.0-r1 due to the self-referential union type containing leafrefs. Applications that use libyang to parse untrusted input yang files may crash.

A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.

A NULL pointer dereference is present in libyang before v1.0-r3 in the function lysextensioninstancesfree() due to a copy of unresolved extensions in lysrestrdup(). Applications that use libyang to parse untrusted input yang files may crash.

An invalid memory access flaw is present in libyang before v1.0-r3 in the function resolvefeaturevalue() when an if-feature statement is used inside a bit. Applications that use libyang to parse untrusted input yang files may crash.

A segmentation fault is present in yyparse in libyang before v1.0-r1 due to a malformed pattern statement value during lysparsepath parsing.

A double-free is present in libyang before v1.0-r1 in the function yyparse() when an empty description is used. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.

A double-free is present in libyang before v1.0-r1 in the function yyparse() when an organization field is not terminated. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.

In all versions of libyang before 1.0-r5, a stack-based buffer overflow was discovered in the way libyang parses YANG files with a leaf of type "bits". An application that uses libyang to parse untrusted YANG files may be vulnerable to this flaw, which would allow an attacker to cause a denial of service or possibly gain code execution.

In all versions of libyang before 1.0-r5, a stack-based buffer overflow was discovered in the way libyang parses YANG files with a leaf of type "identityref". An application that uses libyang to parse untrusted YANG files may be vulnerable to this flaw, which would allow an attacker to cause a denial of service or possibly gain code execution.