{"id":"CVE-2026-47767","aliases":["GHSA-fqc7-9xjw-jrh3"],"url":"https://o3.security/vulnerability/CVE-2026-47767","summary":"Symfony: SymfonyRuntime CVE-2024-50340 Patch Bypass: Web Requests Can Still Set APP_ENV/APP_DEBUG via parse_str/SAPI Argv Mismatch","details":"### Description\n\nCVE-2024-50340 (GHSA-x8vp-gf4q-mw5j) addressed an issue where, with `register_argc_argv=On`, a crafted query string let an unauthenticated GET change the kernel environment and debug flag by feeding `--env`/`--no-debug` through `$_SERVER['argv']`. The fix shipped in `symfony/runtime` 5.4.46 / 6.4.14 / 7.1.7 gated the argv read on `empty($_GET)` as a proxy for \"is this a CLI invocation\".\n\nThat proxy is unsafe: `parse_str()` (which builds `$_GET`) and the web SAPI (which builds `$_SERVER['argv']` from the raw query when `register_argc_argv=On`) do not agree on every input, so an attacker can craft a query that leaves `$_GET` empty while `$_SERVER['argv']` carries the attacker's flags. `SymfonyRuntime::getInput()` then parses them, restoring the exact primitive CVE-2024-50340 was meant to prevent.\n\nPreconditions and impact match the original CVE: web SAPI, `register_argc_argv=On`, app booted through `symfony/runtime`; from an unauthenticated GET an attacker can flip `APP_ENV` and toggle `APP_DEBUG`.\n\n### Resolution\n\n`SymfonyRuntime` now gates the argv read on `isset($_SERVER['QUERY_STRING'])` rather than on `empty($_GET)`. `QUERY_STRING` is the same input the SAPI uses to build argv, so the security check and the thing it protects no longer parse different sources. Worker SAPIs (FrankenPHP / RoadRunner / Swoole) keep working because the runtime constructor runs once at boot when `QUERY_STRING` is unset.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/3228c3806ee511008bea19a95084d460b17e5d25) for branch 5.4.\n\n### Credits\n\nSymfonyRuntime would like to thank 0xEr3n for reporting the issue and Nicolas Grekas for providing the fix.","published":"2026-07-14T18:38:36.513Z","modified":"2026-08-12T03:51:22.747599270Z","cvss":null,"epss":{"score":0.00721,"percentile":0.52305,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"symfony/runtime","fixedVersion":"5.4.52"},{"ecosystem":"Packagist","name":"symfony/runtime","fixedVersion":"6.4.40"},{"ecosystem":"Packagist","name":"symfony/runtime","fixedVersion":"7.4.12"},{"ecosystem":"Packagist","name":"symfony/runtime","fixedVersion":"8.0.12"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"5.4.52"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"6.4.40"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"7.4.12"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"8.0.12"}],"fix":{"url":"https://github.com/symfony/symfony/commit/3228c3806ee511008bea19a95084d460b17e5d25","label":"symfony/symfony@3228c38"},"references":[{"type":"WEB","url":"https://github.com/symfony/symfony/releases/tag/v5.4.52"},{"type":"WEB","url":"https://github.com/symfony/symfony/releases/tag/v6.4.40"},{"type":"WEB","url":"https://github.com/symfony/symfony/releases/tag/v7.4.12"},{"type":"WEB","url":"https://github.com/symfony/symfony/releases/tag/v8.0.12"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47767.json"},{"type":"ADVISORY","url":"https://github.com/symfony/symfony/security/advisories/GHSA-fqc7-9xjw-jrh3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47767"},{"type":"FIX","url":"https://github.com/symfony/symfony/commit/3228c3806ee511008bea19a95084d460b17e5d25"},{"type":"PACKAGE","url":"https://github.com/symfony/symfony"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:22.747599270Z"}}