# CVE-2026-111879: Perl DBI DBD::DBM lock release on failed open

Source: https://junglewise.ai/threats/cve-2026-111879-dbi-versions-before-1-656-for-perl-hang-on-a-later-open-of-a-dbd  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-111879 · Severity: info · Published 2026-10-20

The Perl DBI module's DBD::DBM driver fails to release a file lock when certain table open operations fail, causing subsequent attempts to access the same table to hang indefinitely. This affects database applications using DBM tables with invalid serializer configurations, potentially leading to application freezes and denial of service.

Technologies: [Perl DBI](https://junglewise.ai/threats/technologies/perl-dbi). Vendors: [Perl](https://junglewise.ai/threats/vendors/perl).

## Quick answers

**Is CVE-2026-111879 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111879 being exploited in the wild.

**How severe is CVE-2026-111879?** Informational severity, published 20 October 2026.

**Which products and versions are affected?** Perl DBI before 1.656.

**Is there a fix for CVE-2026-111879?** Yes: fixed in DBI 1.656. Until then: Avoid using invalid dbm_mldbm serializer classes or missing data files in DSN or connection attributes; validate configuration before opening DBM tables. Alternatively, restart affected processes to release stale locks. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-111879 attacked?** It is attacked with local access or over the network, in a software library.

**Am I affected by CVE-2026-111879?** Check whether you run Perl DBI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in DBI 1.656

Avoid using invalid dbm_mldbm serializer classes or missing data files in DSN or connection attributes; validate configuration before opening DBM tables. Alternatively, restart affected processes to release stale locks.

## Technical details

A bug in DBD::DBM's open_data method causes the exclusive flock on a table's lock file to persist after a croak exception when validation of the dbm_mldbm serializer, tie operation, or data file check fails. The lock is held by $meta->{lockfh} which remains cached on the database handle even though the table object is never blessed. Subsequent opens of that table—even through separate database handles in the same or different processes—block forever on flock() with no timeout.

## Affected products

- Perl DBI before 1.656

## Timeline

- 2026-10-20: disclosed
- 2026-10-17: patched

## References

- [https://cpan.org/modules](https://cpan.org/modules)
- [https://github.com/perl5-dbi/dbi/commit/99bbf2ab9d137e6f042a770bd3bbba3bc0b3a901.patch](https://github.com/perl5-dbi/dbi/commit/99bbf2ab9d137e6f042a770bd3bbba3bc0b3a901.patch)

## Related threats

- [Perl DBI type confusion in dbi_profile leading to crash](https://junglewise.ai/threats/cve-2026-108518-dbi-versions-before-1-656-for-perl-crash-via-type-confusion-in)
- [Perl DBI FetchHashKeyName integer value handling integer overflow](https://junglewise.ai/threats/cve-2026-88816-dbi-versions-before-1-654-for-perl-incorrectly-treat-numeric)