Vulnerability 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.
Related Weaknesses (CWE)
References
- https://github.com/boazsegev/facil.io/commit/5128747363055201d3ecf0e29bf0a961703
- https://github.com/boazsegev/facil.io/security/advisories/GHSA-2x79-gwq3-vxxm
- https://github.com/boazsegev/facil.io/security/advisories/GHSA-2x79-gwq3-vxxm
FAQ
What is CVE-2026-41146?
CVE-2026-41146 is a documented vulnerability. 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 start...
How severe is CVE-2026-41146?
CVSS scoring is not yet available for CVE-2026-41146. Check NVD for updates.
Is there a patch for CVE-2026-41146?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.