# CVE-2025-61021: OpenLink Virtuoso OpenSource DoS in sqlo_natural_join_cond

Source: https://junglewise.ai/threats/cve-2025-61021-openlink-virtuoso-opensource-dos-in-sqlo-natural-join-cond  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-23. Updated: 2026-06-23  
License: CC BY 4.0 with a link back

CVE-2025-61021 · Severity: info · CVSS 6.5 · Published 2026-06-23

OpenLink Virtuoso is a high-performance database and middleware platform used for managing large-scale data. A vulnerability in its SQL processing engine allows an attacker to crash the database service by sending specifically crafted database queries. This results in a denial-of-service (DoS) condition, potentially disrupting business operations and data availability until the service is manually restarted.

Technologies: [OpenLink Software Virtuoso OpenSource](https://junglewise.ai/threats/technologies/virtuoso-opensource). Vendors: [OpenLink Software](https://junglewise.ai/threats/vendors/openlink-software).

## Quick answers

**Is CVE-2025-61021 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-61021 being exploited in the wild.

**How severe is CVE-2025-61021?** Informational severity, with a CVSS score of 6.5, published 23 June 2026.

**Which products and versions are affected?** OpenLink Software Virtuoso OpenSource 7.2.11.

**Is there a fix for CVE-2025-61021?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2025-61021 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2025-61021?** Check whether you run OpenLink Software Virtuoso OpenSource 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.

## Technical details

A Denial of Service (DoS) vulnerability exists in OpenLink Virtuoso OpenSource v7.2.11 within the sqlo_natural_join_cond component. The issue is triggered during the compilation or execution of complex SQL statements involving NATURAL JOIN operations, subqueries, and specific table references. An attacker with the ability to execute SQL queries (authenticated user) can provide a crafted statement that causes a null pointer dereference or similar memory corruption, leading to a daemon crash. The vulnerability was identified via fuzzing and confirmed in the 7.2.11 release and associated Docker images. No official patch was explicitly detailed in the advisory, though it was reported via the project's GitHub issue tracker.

## Affected products

- OpenLink Virtuoso OpenSource 7.2.11

## Timeline

- 2024-01-07: disclosed: Issue reported on GitHub by fuboat
- 2026-06-23: advisory: CVE published to NVD

## References

- [https://github.com/openlink/virtuoso-opensource/issues/1223](https://github.com/openlink/virtuoso-opensource/issues/1223)

## Related threats

- [OpenLink Virtuoso OpenSource Denial of Service in sqlo_untry](https://junglewise.ai/threats/cve-2025-61029-openlink-virtuoso-opensource-denial-of-service-in-sqlo-untry)
- [OpenLink Virtuoso OpenSource DoS in sqlo_try_in_loop](https://junglewise.ai/threats/cve-2025-61024-openlink-virtuoso-opensource-dos-in-sqlo-try-in-loop)
- [OpenLink Virtuoso OpenSource Denial of Service in time_t_to_dt](https://junglewise.ai/threats/cve-2025-61028-openlink-virtuoso-opensource-denial-of-service-in-time-t-to-dt)
- [OpenLink Virtuoso OpenSource Denial of Service in t_set_push](https://junglewise.ai/threats/cve-2025-61027-openlink-virtuoso-opensource-denial-of-service-in-t-set-push)
- [OpenLink Virtuoso OpenSource Denial of Service in sslr_qst_get](https://junglewise.ai/threats/cve-2025-61025-openlink-virtuoso-opensource-denial-of-service-in-sslr-qst-get)