facil.io and downstream iodine ruby gem vulnerable to uncontrolled resource consumption and loop with unreachable exit condition_CVE-2026-41146

{
    "lastseen": "",
    "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.",
    "published": "2026-04-22T01:07:28.660Z",
    "modified": "2026-04-22T01:07:28.660Z",
    "type": "cve",
    "title": "facil.io and downstream iodine ruby gem vulnerable to uncontrolled resource consumption and loop with unreachable exit condition",
    "source": "GitHub_M",
    "references": "https://github.com/boazsegev/facil.io/security/advisories/GHSA-2x79-gwq3-vxxm\nhttps://github.com/boazsegev/facil.io/commit/5128747363055201d3ecf0e29bf0a961703c9fa0",
    "id": "CVE-2026-41146",
    "bulletinFamily": "",
    "cwe": [
        "CWE-400",
        "CWE-835"
    ],
    "cvelist": null,
    "sourceData": "boazsegev facil.io < 5128747363055201d3ecf0e29bf0a961703c9fa0\nboazsegev iodine < 0.7.59",
    "sourceHref": "",
    "cvss": {
        "score": 8.7,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "facil.io",
    "version": "< 5128747363055201d3ecf0e29bf0a961703c9fa0",
    "vendor": "boazsegev",
    "ai_description": "Infinite loop in JSON parsing due to nested values starting with 'i' or 'I', leading to uncontrolled resource consumption",
    "ai_severity": "High",
    "ai_vendor": "boazsegev",
    "ai_product": "facil.io, iodine",
    "ai_version": "< 5128747363055201d3ecf0e29bf0a961703c9fa0, < 0.7.59",
    "ai_score": 8.7
}