CVE-2025-61027 Overview
CVE-2025-61027 affects the t_set_push component of OpenLink virtuoso-opensource version 7.2.11. Attackers can trigger a Denial of Service (DoS) condition by submitting crafted SQL statements to the database engine. The flaw exists in an open-source hybrid database that combines relational, graph, and RDF data management, making it a common backend for SPARQL endpoints and linked data services. Successful exploitation crashes or hangs the Virtuoso process, disrupting availability for dependent applications.
Critical Impact
Crafted SQL statements processed by t_set_push cause a Denial of Service against Virtuoso 7.2.11, interrupting database availability for all connected clients.
Affected Products
- OpenLink Virtuoso Open Source v7.2.11
- Deployments exposing SQL or SPARQL interfaces backed by the affected t_set_push code path
- Downstream applications relying on Virtuoso 7.2.11 as a data backend
Discovery Timeline
- 2026-06-23 - CVE-2025-61027 published to the National Vulnerability Database (NVD)
- 2026-06-23 - Last updated in NVD database
Technical Details for CVE-2025-61027
Vulnerability Analysis
The vulnerability resides in the t_set_push component of virtuoso-opensource v7.2.11. According to the issue tracker reference, specifically crafted SQL statements drive the component into a state that terminates the server process or exhausts resources. The result is a Denial of Service against the database engine.
Virtuoso parses incoming SQL through multiple internal data structures, and t_set_push operates on transaction-scoped set storage used by the query execution pipeline. When malformed or boundary-violating inputs reach this routine, the engine fails to handle them safely, leading to a crash or unresponsive state.
The public EPSS score for this CVE is low, reflecting limited observed exploitation attempts at this time. However, network-facing Virtuoso deployments that accept untrusted SQL remain exposed until patched.
Root Cause
The root cause is improper handling of attacker-controlled SQL input within the t_set_push routine. The component does not adequately validate or constrain inputs before operating on internal set structures, allowing crafted statements to reach an unsafe execution path.
Attack Vector
An attacker submits a crafted SQL statement to a Virtuoso instance over any interface that accepts SQL, such as the iSQL endpoint or application-mediated query channels. Authentication requirements depend on deployment configuration. Once the malicious query reaches t_set_push, the server enters a faulty state and stops servicing requests.
No verified exploit code is publicly catalogued. Technical discussion is available in the OpenLink Virtuoso GitHub Issue #1232.
Detection Methods for CVE-2025-61027
Indicators of Compromise
- Unexpected termination or hang of the virtuoso-t process accompanied by missing graceful shutdown messages in virtuoso.log.
- Repeated client connection errors or query timeouts originating from a single source IP submitting malformed SQL.
- Spikes in CPU or memory consumption on the Virtuoso host immediately preceding a service crash.
Detection Strategies
- Monitor Virtuoso server logs for abnormal query failures, stack traces, or assertions referencing set-handling routines.
- Inspect SQL and SPARQL traffic for syntactically unusual statements directed at exposed Virtuoso endpoints.
- Correlate database process restarts with preceding query patterns to identify likely trigger statements.
Monitoring Recommendations
- Enable process-level health checks on the Virtuoso service and alert on unplanned restarts.
- Forward Virtuoso logs to a centralized logging or SIEM platform for retention and pattern analysis.
- Track query latency and error rate metrics to identify denial-of-service attempts early.
How to Mitigate CVE-2025-61027
Immediate Actions Required
- Restrict network access to Virtuoso SQL and SPARQL interfaces using firewall rules or reverse proxies.
- Require authentication for all client connections and remove anonymous query privileges where possible.
- Audit application code paths that forward user input into Virtuoso to ensure parameterization and input validation.
Patch Information
No fixed version has been published in the enriched CVE data at the time of writing. Monitor the OpenLink Virtuoso GitHub repository for an official fix and upgrade once a patched release is announced.
Workarounds
- Place Virtuoso behind a query gateway that rejects unexpected SQL constructs before they reach the database engine.
- Limit accepted statement types per role using Virtuoso's built-in account and grant model.
- Apply rate limiting on database-facing endpoints to slow brute-force probing for crash-triggering inputs.
# Configuration example: restrict Virtuoso listener to localhost in virtuoso.ini
[Parameters]
ServerPort = 1111
ServerThreads = 20
DisableUnixSocket = 0
# Bind only to loopback; expose via authenticated reverse proxy
ListenIP = 127.0.0.1
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
