CVE-2026-24425

Description

When using the sandbox with a SourcePolicyInterface, Twig does not always apply the sandbox restriction that forbids non-Closure callbacks for callback-accepting filters.

The issue affects the sort, filter, map, and reduce filters.

In the affected versions, the runtime check that rejects non-Closure callbacks in sandbox mode does not use the current template Source. As a result, when the sandbox is enabled through a source policy instead of being enabled globally, Twig can incorrectly treat the current execution as non-sandboxed for these callback checks.

This can allow user-controlled templates to pass arbitrary PHP callables to callback-accepting filters even though the template is being sandboxed through a source policy.

The issue happens when all these conditions are met:

• The sandbox is not enabled globally;
• A SourcePolicyInterface enables the sandbox for the rendered template;
• The template uses one of the sort, filter, map, or reduce filters;
• The callback is not a Closure.

Resolution

The patch makes callback sandbox checks source-aware by propagating the current template Source to callback-accepting filters and using it when deciding whether sandbox restrictions apply.

Credits

We would like to thank XavLim and Wade Sparks for reporting the issue and Fabien Potencier for fixing the issue.

CVE-2026-24425 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.26.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-24425? CVE-2026-24425 is a high-severity security vulnerability in twig/twig (composer), affecting versions >= 2.16.0, <= 2.16.1. It is fixed in 3.26.0.
2. How severe is CVE-2026-24425? CVE-2026-24425 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of twig/twig are affected by CVE-2026-24425? twig/twig (composer) versions >= 2.16.0, <= 2.16.1 is affected.
4. Is there a fix for CVE-2026-24425? Yes. CVE-2026-24425 is fixed in 3.26.0. Upgrade to this version or later.
5. Is CVE-2026-24425 exploitable, and should I be worried? Whether CVE-2026-24425 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-24425 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-24425? Upgrade twig/twig to 3.26.0 or later.