CVE-2026-41146
Uncontrolled resource consumption and loop with unreachable exit condition in facil.io and downstream iodine ruby gem
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | iodine | <= 0.7.58 | none recorded |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-2x79-gwq3-vxxm
- https://github.com/boazsegev/facil.io/security/advisories/GHSA-2x79-gwq3-vxxm
- https://nvd.nist.gov/vuln/detail/CVE-2026-41146
- https://github.com/boazsegev/facil.io/commit/5128747363055201d3ecf0e29bf0a961703c9fa0
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/iodine/CVE-2026-41146.yml