CVE-2026-73194

Beschreibung

DBI versions before 1.652 for Perl allow a heap out-of-bounds write via an unvalidated numeric placeholder that sets the binder counter in preparse. preparse reserves seven output bytes per input byte, the width of the longest -:p99999- expansion. The -:N- branch parses the number with `atoi(src)` and assigns it to the binder counter with no range check, so a statement containing -:2147483648- leaves the counter negative (-2147483648 with glibc, where atoi wraps). Each following -?- then expands through `sprintf(start, -:p%d-, idx++)` to -:p-2147483648-, 14 bytes with the terminating NUL where the buffer budgets 7. The placeholder limit added in 1.650 tests the counter against 99,999, which a negative counter passes. Any caller that preparses an untrusted statement into -:pN- style placeholders gets a heap out-of-bounds write that grows with the number of -?- marks following the poisoned placeholder. The -?- and -%s- return styles compare the parsed number against the expected sequence and error out, and are unaffected.