---
id: CVE-2026-78030
title: >-
  DBI versions before 1.653 for Perl load arbitrary modules via unvalidated
  dbm_type and dbm_mldbm attributes in DBD::DBM.


  DBD::DBM passes the dbm_type and dbm_mldbm connect attributes to require
  without checking that the value names a mo…
summary: >-
  DBI versions before 1.653 for Perl load arbitrary modules via unvalidated
  dbm_type and dbm_mldbm attributes in DBD::DBM.


  DBD::DBM passes the dbm_type and dbm_mldbm connect attributes to require
  without checking that the value names a mo…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-470
product: DBI
affected:
  - DBI < 1.653
published: '2026-09-19'
updated: '2026-09-20'
sourceUpdated: '2026-09-20T01:16:30.017'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-78030'
references:
  - url: >-
      https://github.com/perl5-dbi/dbi/commit/315c6ce703b8b3cbe9188062d9ec80730293554a.patch
    label: 9b29abf9-4ab0-4765-b253-1875cd9b441e
  - url: 'https://github.com/perl5-dbi/dbi/security/advisories/GHSA-wqmw-wqwx-3fr7'
    label: 9b29abf9-4ab0-4765-b253-1875cd9b441e
  - url: 'https://metacpan.org/release/HMBRAND/DBI-1.653/changes'
    label: 9b29abf9-4ab0-4765-b253-1875cd9b441e
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/19/4'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-20T00:05:25.993244Z'
ingestedAt: '2026-09-19T11:01:56.651Z'
epss: 0.00725
epssPercentile: 0.52193
---

## Overview

DBI versions before 1.653 for Perl load arbitrary modules via unvalidated dbm_type and dbm_mldbm attributes in DBD::DBM.

DBD::DBM passes the dbm_type and dbm_mldbm connect attributes to require without checking that the value names a module. require treats a path-shaped string as a literal filename and does not consult @INC, so the attribute chooses the file that Perl loads and runs.

The MLDBM::Serializer:: prefix that DBD::DBM prepends to dbm_mldbm is not a boundary: only the :: separators are rewritten to /, so a value containing / traverses out of the serializer directory. The value is also assigned to $MLDBM::Serializer, which MLDBM requires the same way when it ties the table.

A caller that lets an untrusted party influence either attribute, for example through a DSN fragment or a parameter that selects a storage backend, runs the file-scope code of whatever module the value names.

For example,

    my $dsn = "dbi:DBM:f_dir=/var/db;dbm_type=../../Untrusted.pm"
    my $dbh = DBI->connect( $dsn );

Note that DBD::Gofer forwards connect attributes to the server side, and DBI::ProxyServer checks only that a DSN starts with a driver prefix.

## Remediation

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