CVE-2026-47767: Symfony Runtime environment variable manipulation via query string bypass

CVE-2026-47767 · Severity: medium · CVSS 4 · Published 2026-07-14

Symfony is a popular PHP framework used to build web applications. A vulnerability in its runtime component allows an attacker to manipulate application settings, such as enabling debug mode or changing the environment configuration, via a specially crafted web request. This could lead to the exposure of sensitive system information or unauthorized changes to how the application behaves.

Technologies: symfony/symfony (Packagist). Vendors: Packagist, Symfony.

Quick answers

Is CVE-2026-47767 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-47767 being exploited in the wild.
How severe is CVE-2026-47767?
Medium severity, with a CVSS score of 4, published 14 July 2026.
Which products and versions are affected?
symfony/runtime (Packagist) ECOSYSTEM:introduced=5.4.46,fixed=5.4.52; symfony/symfony (Packagist) ECOSYSTEM:introduced=5.4.46,fixed=5.4.52; Symfony Runtime >= 5.4.46, < 5.4.52; >= 6.4.14, < 6.4.40; >= 7.1.7, < 7.4.12; >= 8.0.0-BETA1, < 8.0.12, >= 5.4.46, < 5.4.52; >= 6.4.14, < 6.4.40; >= 7.1.7, < 7.4.12; >= 8.0.0, < 8.0.12.
Is there a fix for CVE-2026-47767?
Yes. symfony/runtime (Packagist): upgrade to 5.4.52 or later; symfony/symfony (Packagist): upgrade to 5.4.52 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-47767 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-47767?
Check whether you run symfony/runtime (Packagist), symfony/symfony (Packagist) or Symfony Runtime at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • symfony/runtime (Packagist): upgrade to 5.4.52 or later
    composer require symfony/runtime:^5.4.52
  • symfony/symfony (Packagist): upgrade to 5.4.52 or later
    composer require symfony/symfony:^5.4.52

Technical details

This vulnerability is a bypass of the fix for CVE-2024-50340. The original fix attempted to gate runtime 'argv' parsing by checking if the $_GET superglobal was empty. However, a discrepancy between how parse_str() and the web SAPI handle query strings allows an attacker to craft a request where $_GET remains empty while $_SERVER['argv'] still contains attacker-controlled flags. By injecting flags such as --env or --no-debug, an attacker can override critical application configurations (APP_ENV or APP_DEBUG). This is classified as an interpretation conflict (CWE-436). The issue is resolved by gating 'argv' parsing on $_SERVER['QUERY_STRING'] instead of $_GET.

Affected products

  • Symfony symfony/symfony >= 5.4.46, < 5.4.52; >= 6.4.14, < 6.4.40; >= 7.1.7, < 7.4.12; >= 8.0.0-BETA1, < 8.0.12
  • Symfony symfony/runtime >= 5.4.46, < 5.4.52; >= 6.4.14, < 6.4.40; >= 7.1.7, < 7.4.12; >= 8.0.0-BETA1, < 8.0.12

Identifiers

  • CVE-2026-47767
  • GHSA-fqc7-9xjw-jrh3

Timeline

  • 2026-07-14: disclosed
  • 2026-07-14: advisory
  • 2026-05-20: patched: Release date of fixed versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

References

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