The d_print_comp function in cp-demangle.c in libiberty allows remote attackers to cause a denial of service (segmentation fault and crash) via a crafted binary, which triggers infinite recursion and a buffer overflow, related to a node having "itself as ancestor more than once."

References

• https://nvd.nist.gov/vuln/detail/CVE-2016-4491
• https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70909
• https://gcc.gnu.org/ml/gcc-patches/2016-05/msg00105.html
• http://www.openwall.com/lists/oss-security/2016/05/05/5
• http://www.securityfocus.com/bid/90016