{"id":"DEBIAN-CVE-2026-85644","details":"XS::Parse::Infix versions from 0.40 through 0.49 for Perl treat a number as an array reference.  The wrapper function XS::Parse::Infix generates for a list-associative infix operator checks whether arguments are array references, but it tests using SvRV() rather than SvROK(). SvRV() reads a union slot that only holds a referent once SvROK(sv) is true, so the guard never validates that it is a reference. For an IV or NV that slot holds the number itself, SvRV() returns the caller's value and SvTYPE() dereferences it at offset 12. This will generally result in a segmentation fault.  An application that hands the wrapper a list built from decoded input (for example, from JSON) lets whoever supplies a number in that list choose the address that the interpreter dereferences.  An ordinary string's byte 12 is rarely SVt_PVAV so the guard croaks by luck, but an attacker-crafted string carrying 0x0b there passes, and the buffer is then used as an AV head, with AvARRAY taken from bytes 16-23 and its entries pushed onto the Perl stack as live SVs.  A simple proof-of-concept uses the zip operator:      use Syntax::Operator::Zip 'zip';      my @args = ([1], 2);     zip(@args);","modified":"2026-10-04T17:00:12.104580939Z","published":"2026-09-28T17:17:51.127Z","upstream":["CVE-2026-85644"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-85644"}],"affected":[{"package":{"name":"libxs-parse-keyword-perl","ecosystem":"Debian:13","purl":"pkg:deb/debian/libxs-parse-keyword-perl?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.48-2","0.49-1","0.51-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85644.json"}},{"package":{"name":"libxs-parse-keyword-perl","ecosystem":"Debian:14","purl":"pkg:deb/debian/libxs-parse-keyword-perl?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.51-1"}]}],"versions":["0.48-2","0.49-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85644.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}