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

Published Aug 15, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Solution

Upgrade to DBI 1.652 or later.


Vendor Workaround

For deployments that cannot be upgraded, limit SQL statements to 99,999 placeholders.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4764-1 libdbi-perl security update
Debian DSA Debian DSA DSA-6473-1 libdbi-perl security update
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Perl5-dbi
Perl5-dbi dbi
Vendors & Products Perl5-dbi
Perl5-dbi dbi
Type Values Removed Values Added
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.
Title 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
Weaknesses CWE-1284
CWE-787
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Aug 17, 2026, 8:29 PM
Reserved
Aug 11, 2026, 11:58 AM
Status
Awaiting Analysis
Published
Aug 15, 2026, 1:17 PM
Modified
Aug 28, 2026, 3:42 PM
Severity
Important
Public date
Aug 15, 2026, 12:09 PM