Vulnerability Description
Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the byte length carried over from the preceding multiaddr argument instead. Both addresses occupy a 4-byte field, so a valid multiaddr lets a source of any length pass the check, and the source is then copied into the 4-byte imr_sourceaddr field with a fixed-size copy. A source shorter than 4 bytes is not rejected, and the copy reads up to 3 bytes past the end of its buffer. Calling pack_ip_mreq_source() with a source value shorter than 4 bytes copies adjacent heap memory into the returned packed structure.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/Perl/perl5/commit/de19a0b0ad1900fef976c5c1400bd8f11ec6c6cb.pa
- https://metacpan.org/release/PEVANS/Socket-2.041/changes
- http://www.openwall.com/lists/oss-security/2026/06/15/10
FAQ
What is CVE-2026-12087?
CVE-2026-12087 is a vulnerability with a CVSS score of 9.1 (CRITICAL). Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the...
How severe is CVE-2026-12087?
CVE-2026-12087 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-12087?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.