CVE-2026-73194: 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

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-15 · updated 2026-08-28
Weakness: CWE-787

Description

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.

References

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