CVE-2026-86463: Vulnerability in Apache Software Foundation Apache CXF
Description
Apache CXF's FIQL query parser has a vulnerability in how it searches for operators in query expressions. The search pattern can get stuck trying many combinations when it encounters a long string without an operator, causing the parser to consume excessive CPU time. An attacker can send a crafted query to make the server use up CPU resources, potentially slowing down or stopping other requests. The fix was to limit FIQL expressions to 4 KiB by default, preventing attackers from sending extremely long inputs while still allowing normal queries. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
Affected software
Apache Software Foundation
Apache CXF
pkg:maven/Apache Software Foundation/org.apache.cxf:cxf-rt-rs-extension-searchRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The FIQL query parser in Apache CXF has a flaw in its operator search logic that causes it to attempt many combinations when encountering long strings without operators. This results in excessive CPU consumption, enabling an attacker to degrade service availability by sending crafted queries. The vulnerability is addressed by imposing a default 4 KiB limit on FIQL expressions, preventing excessively long inputs. Fixed versions are 4.2.4, 4.1.9, and 3.6.13.
Potential Impact
An attacker can exploit this vulnerability to cause high CPU usage on the server running Apache CXF, potentially slowing down or halting processing of legitimate requests. This leads to a denial of service condition but does not indicate direct data compromise or code execution.
Mitigation Recommendations
Upgrade Apache CXF to version 4.2.4, 4.1.9, or 3.6.13 or later, where the vulnerability is fixed by limiting FIQL expression length to 4 KiB. This prevents attackers from sending excessively long queries that trigger high CPU consumption.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-09-07T14:23:09.392Z
- State
- PUBLISHED
Threat ID: 6ac8c31f2cdf04f6564c0cda
Added to database: 10/09/2026, 10:34:07 UTC
Last enriched: 10/09/2026, 10:49:04 UTC
Last updated: 10/09/2026, 18:57:32 UTC
Views: 12
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