CVE-2026-47212 Symfony: Twilio SMS Notifier allows unauthenticated webhook injection due to missing X-Twilio-Signature verification

What is CVE-2026-47212?

CVE-2026-47212 is a medium-severity missing authorization vulnerability in Sensiolabs Symfony, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 6.4.40, 7.4.12, and 8.0.12, TwilioRequestParser::doParse() received the configured webhook secret but ignored the X-Twilio-Signature HMAC header, allowing unauthenticated POST requests to inject forged Twilio status payloads. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.

Weakness: CWE-347, CWE-306

Which versions are affected by CVE-2026-47212?

12 open source packages ship an affected version, including symfony/symfony and symfony/twilio-notifier. It affects 1 product.

Products include Sensiolabs Symfony.

How do I fix CVE-2026-47212?

Upgrade symfony/symfony to a fixed version for your release line: 6.4.40, 7.4.12 or 8.0.12.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-47212 being exploited?

There is no known exploitation of CVE-2026-47212 in the wild and no public exploit code.

Other vulnerabilities in Sensiolabs Symfony

• CVE-2019-11325 Improper Input Validation in Symfony Critical 9.8
• CVE-2017-11365 Symfony Incorrect Access Control Critical 9.8
• CVE-2019-10913 Invalid HTTP method overrides allow possible XSS or other attacks in Symfony Critical 9.8
• CVE-2018-11407 Symfony Authentication Bypass Critical 9.8
• CVE-2016-2403 Symfony Authentication Bypass Critical 9.8

All Sensiolabs Symfony vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-47212, GHSA-55rj-x2vc-4whq, UBUNTU-CVE-2026-47212.