DBI versions before 1.654 for Perl incorrectly treat numeric values as strings in FetchHashKeyName. fetchrow_hashref uses the string pointer of the FetchHashKeyName attribute as the key name without stringifying it first

Overview

DBI versions before 1.654 for Perl incorrectly treat numeric values as strings in FetchHashKeyName.

fetchrow_hashref uses the string pointer of the FetchHashKeyName attribute as the key name without stringifying it first. When FetchHashKeyName has been set to an integer (IV) or floating-point (NV) value, that pointer is invalid, so reading the key name triggers a segmentation fault.

This can be triggered with the following code:

my $dbh = DBI->connect( "dbi:ExampleP:", "", "", { RaiseError => 0, PrintError => 0 } ); $dbh->{FetchHashKeyName} = 42;

my $sth = $dbh->prepare("select mode, size, name from ."); $sth->execute; $sth->fetchrow_hashref;

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-30 · vex