CVE-2026-41146
Severity CVSS v4.0:
HIGH
Type:
CWE-400
Uncontrolled Resource Consumption ('Resource Exhaustion')
Publication date:
22/04/2026
Last modified:
22/04/2026
Description
facil.io is a C micro-framework for web applications. Prior to commit 5128747363055201d3ecf0e29bf0a961703c9fa0, `fio_json_parse` can enter an infinite loop when it encounters a nested JSON value starting with `i` or `I`. The process spins in user space and pegs one CPU core at ~100% instead of returning a parse error. Because `iodine` vendors the same parser code, the issue also affects `iodine` when it parses attacker-controlled JSON. The smallest reproducer I found is `[i`. The quoted-value form that originally exposed the issue, `[""i`, reaches the same bug because the parser tolerates missing commas and then treats the trailing `i` as the start of another value. Commit 5128747363055201d3ecf0e29bf0a961703c9fa0 fixes the issue.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH