@node-oauth/oauth2-server: PKCE code_verifier ABNF not enforced in token exchange allows brute-force redemption of intercepted authorization codes_CVE-2026-41213

{
    "lastseen": "",
    "description": "@node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force code_verifier guesses online until token issuance succeeds.",
    "published": "2026-04-23T18:33:42.365Z",
    "modified": "2026-04-23T18:33:42.365Z",
    "type": "cve",
    "title": "@node-oauth/oauth2-server: PKCE code_verifier ABNF not enforced in token exchange allows brute-force redemption of intercepted authorization codes",
    "source": "GitHub_M",
    "references": "https://github.com/node-oauth/node-oauth2-server/security/advisories/GHSA-jhm7-29pj-4xvf",
    "id": "CVE-2026-41213",
    "bulletinFamily": "",
    "cwe": [
        "CWE-307",
        "CWE-1289"
    ],
    "cvelist": null,
    "sourceData": "node-oauth node-oauth2-server < 5.3.0",
    "sourceHref": "",
    "cvss": {
        "score": 5.9,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "node-oauth2-server",
    "version": "< 5.3.0",
    "vendor": "node-oauth",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}