CVE-2026-61483 Overview
CVE-2026-61483 is an uncontrolled recursion vulnerability [CWE-674] affecting Apache Lucy, a full-text search engine library. The flaw impacts all versions of Apache Lucy, and the project is retired. The Apache Software Foundation has stated that no patched release will be produced. Users are advised to migrate to an alternative search library or restrict access to trusted users only.
The vulnerability allows an attacker supplying crafted input to trigger unbounded recursive processing. This can exhaust the call stack and terminate the process, producing a denial-of-service condition.
Critical Impact
All versions of Apache Lucy are affected and no fix will be released. Operators must migrate away from Lucy or restrict input to trusted sources.
Affected Products
- Apache Lucy (all versions)
- Applications embedding the Apache Lucy library
- Retired Apache Lucy releases without upstream maintenance
Discovery Timeline
- 2026-08-05 - CVE-2026-61483 published to the National Vulnerability Database (NVD)
- 2026-08-05 - Last updated in NVD database
Technical Details for CVE-2026-61483
Vulnerability Analysis
CVE-2026-61483 is classified under CWE-674: Uncontrolled Recursion. The defect exists in code paths that recursively process user-controlled input without enforcing a depth bound. When an attacker provides input with deep nesting or self-referential structure, the parser calls itself repeatedly until stack memory is exhausted.
Stack exhaustion typically produces a segmentation fault or process abort. In a service context, this terminates the search worker and interrupts query handling. Because the Apache Software Foundation has retired the project, the guidance is to migrate rather than patch. Consult the Apache Mailing List Discussion and the Openwall OSS Security Update for the maintainer statement.
Root Cause
The root cause is missing recursion depth validation in input-processing routines. Recursive calls proceed unchecked based on structural attributes of attacker-controlled data. Without a recursion limit or iterative alternative, adversarial input drives the call chain past the platform stack size.
Attack Vector
An attacker who can submit search inputs to a Lucy-backed service can trigger the recursive path. The specific interface depends on the embedding application. Refer to the upstream references for technical detail; no verified proof-of-concept code is published in the enriched advisory data.
Detection Methods for CVE-2026-61483
Indicators of Compromise
- Process crashes or segmentation faults in services that embed Apache Lucy
- Repeated worker restarts correlated with specific inbound search or indexing requests
- Anomalously deep or nested payloads in query and document input logs
Detection Strategies
- Inventory all systems that link against Apache Lucy libraries, including internal search and indexing services
- Instrument the host process to capture core dumps and stack traces on abnormal termination
- Correlate crash timestamps with upstream request logs to identify malicious input patterns
Monitoring Recommendations
- Alert on repeated crashes or restarts of any process containing Lucy code paths
- Monitor request payload size and nesting depth on endpoints backed by Lucy
- Track availability metrics for search services to catch denial-of-service patterns early
How to Mitigate CVE-2026-61483
Immediate Actions Required
- Identify every deployment of Apache Lucy across the environment and mark the project as end-of-life
- Restrict network access to Lucy-backed services so only trusted users and systems can submit queries
- Plan migration to a supported search library such as Apache Lucene or an alternative full-text engine
- Apply input validation at the application layer to reject deeply nested or oversized payloads before they reach Lucy
Patch Information
No patch will be issued. The Apache Software Foundation has retired Apache Lucy and stated it does not plan to release a fixed version. See the Apache Mailing List Discussion for the retirement notice. Migration to a maintained alternative is the required remediation.
Workarounds
- Place Lucy-backed services behind authenticated gateways and remove public network exposure
- Enforce request size and structural depth limits at a reverse proxy or web application firewall
- Sandbox the Lucy process with resource limits so crashes do not degrade neighboring services
- Accelerate migration to a supported search platform to eliminate the exposure permanently
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
