{"id":"GHSA-55rj-x2vc-4whq","aliases":["CVE-2026-47212"],"title":"Symfony: Twilio SMS Notifier allows unauthenticated webhook injection due to missing X-Twilio-Signature verification","description":"### Description\n\nThe Twilio SMS notifier bridge ships a webhook request parser used to authenticate and decode the status callbacks Twilio POSTs to an application's webhook endpoint. Its `doParse(Request $request, #[\\SensitiveParameter] string $secret)` method receives the configured webhook secret but never reads it; it decodes and returns the payload unconditionally, ignoring the `X-Twilio-Signature` HMAC header Twilio sends with each request.\n\nAs a result, an application that wires up the Twilio webhook endpoint accepts **any** POST to that URL, even when a signing secret is configured (the recommended setup). An attacker who knows the endpoint exists can submit forged status payloads, fake delivered / failed / undelivered events, leading to delivery-metrics fraud, downstream automation triggers, etc.\n\n### Resolution\n\n`TwilioRequestParser::doParse()` now requires and verifies the `X-Twilio-Signature` header (HMAC-SHA1 over the full request URL concatenated with the alphabetically-sorted POST parameters, base64-encoded, keyed with the Twilio account auth token) before further processing, using a constant-time comparison.\n\nWhen no secret is configured the behaviour is unchanged: signature verification remains opt-in, but it is now actually enforced once opted in.\n\nApplications behind a TLS-terminating reverse proxy must configure `framework.trusted_proxies` and `framework.trusted_headers` so that `Request::getUri()` returns the public URL Twilio signed.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/8545fb2af6c07dfb5ef0fc8d9bccf86db2c94356) for branch 6.4.\n\n### Credits\n\nSymfony would like to thank Himanshu Anand for reporting the issue and Nicolas Grekas for providing the fix.","severity":"medium","score":4.6,"published":"2026-05-29T21:32:23.000Z","modified":"2026-09-10T03:51:04.682Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"Packagist","name":"symfony/symfony","ranges":[{"events":[{"introduced":"6.4.0"},{"fixed":"6.4.40"}],"type":"ECOSYSTEM"}],"versions":["v6.4.0","v6.4.1","v6.4.10","v6.4.11","v6.4.12","v6.4.13","v6.4.14","v6.4.15","v6.4.16","v6.4.17","v6.4.18","v6.4.19","v6.4.2","v6.4.20","v6.4.21","v6.4.22","v6.4.23","v6.4.24","v6.4.25","v6.4.26","v6.4.27","v6.4.28","v6.4.29","v6.4.3","v6.4.30","v6.4.31","v6.4.32","v6.4.33","v6.4.34","v6.4.35","v6.4.36","v6.4.37","v6.4.38","v6.4.39","v6.4.4","v6.4.5","v6.4.6","v6.4.7","v6.4.8","v6.4.9"],"fixed":["6.4.40"]},{"ecosystem":"Packagist","name":"symfony/symfony","ranges":[{"events":[{"introduced":"7.0.0"},{"fixed":"7.4.12"}],"type":"ECOSYSTEM"}],"versions":["v7.0.0","v7.0.1","v7.0.10","v7.0.2","v7.0.3","v7.0.4","v7.0.5","v7.0.6","v7.0.7","v7.0.8","v7.0.9","v7.1.0","v7.1.0-BETA1","v7.1.0-RC1","v7.1.1","v7.1.10","v7.1.11","v7.1.2","v7.1.3","v7.1.4","v7.1.5","v7.1.6","v7.1.7","v7.1.8","v7.1.9","v7.2.0","v7.2.0-BETA1","v7.2.0-BETA2","v7.2.0-RC1","v7.2.1","v7.2.2","v7.2.3","v7.2.4","v7.2.5","v7.2.6","v7.2.7","v7.2.8","v7.2.9","v7.3.0","v7.3.0-BETA1","v7.3.0-BETA2","v7.3.0-RC1","v7.3.1","v7.3.10","v7.3.11","v7.3.2","v7.3.3","v7.3.4","v7.3.5","v7.3.6","v7.3.7","v7.3.8","v7.3.9","v7.4.0","v7.4.0-BETA1","v7.4.0-BETA2","v7.4.0-RC1","v7.4.0-RC2","v7.4.0-RC3","v7.4.1","v7.4.10","v7.4.11","v7.4.2","v7.4.3","v7.4.4","v7.4.5","v7.4.6","v7.4.7","v7.4.8","v7.4.9"],"fixed":["7.4.12"]},{"ecosystem":"Packagist","name":"symfony/symfony","ranges":[{"events":[{"introduced":"8.0.0"},{"fixed":"8.0.12"}],"type":"ECOSYSTEM"}],"versions":["v8.0.0","v8.0.1","v8.0.10","v8.0.11","v8.0.2","v8.0.3","v8.0.4","v8.0.5","v8.0.6","v8.0.7","v8.0.8","v8.0.9"],"fixed":["8.0.12"]},{"ecosystem":"Packagist","name":"symfony/twilio-notifier","ranges":[{"events":[{"introduced":"6.4.0"},{"fixed":"6.4.40"}],"type":"ECOSYSTEM"}],"versions":["v6.4.0","v6.4.13","v6.4.24","v6.4.3","v6.4.32","v6.4.7","v6.4.8"],"fixed":["6.4.40"]},{"ecosystem":"Packagist","name":"symfony/twilio-notifier","ranges":[{"events":[{"introduced":"7.0.0"},{"fixed":"7.4.12"}],"type":"ECOSYSTEM"}],"versions":["v7.0.0","v7.0.3","v7.0.7","v7.0.8","v7.1.0","v7.1.0-BETA1","v7.1.0-RC1","v7.1.1","v7.1.6","v7.2.0","v7.2.0-BETA1","v7.2.0-RC1","v7.3.0","v7.3.0-BETA1","v7.3.0-RC1","v7.3.10","v7.4.0","v7.4.0-BETA1","v7.4.0-RC1","v7.4.4"],"fixed":["7.4.12"]},{"ecosystem":"Packagist","name":"symfony/twilio-notifier","ranges":[{"events":[{"introduced":"8.0.0"},{"fixed":"8.0.12"}],"type":"ECOSYSTEM"}],"versions":["v8.0.0","v8.0.4"],"fixed":["8.0.12"]}],"references":["https://github.com/symfony/symfony/security/advisories/GHSA-55rj-x2vc-4whq","https://github.com/symfony/symfony/commit/8545fb2af6c07dfb5ef0fc8d9bccf86db2c94356","https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-47212.yaml","https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/twilio-notifier/CVE-2026-47212.yaml","https://github.com/symfony/symfony","https://symfony.com/cve-2026-47212"],"sources":[{"name":"OSV","id":"GHSA-55rj-x2vc-4whq","modified":"2026-09-10T03:51:04.682497296Z","url":"https://osv.dev/vulnerability/GHSA-55rj-x2vc-4whq"}],"assessments":[{"source":"OSV","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U","score":4.6}]}