CVE-2026-46640 in Twig
Twig is a template language for PHP. From 3.15.0 until 3.26.0, _self.(<string>) and import-alias dynamic attribute syntax can concatenate an attacker-controlled string into a MacroReferenceExpression name without identifier validation, causing raw PHP to be emitted into the generated template source and executed at template-load time. This issue is fixed in version 3.26.0.
Quick answer
Symfony Twig should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- Twig 3.15.0 before 3.26.0
Fixed versions
- 3.26.0
How to fix it
CVE-2026-46640 is a remote code execution issue in Twig. Update from Twig 3.15.0 before 3.26.0 to 3.26.0 or newer. Keep it simple: upgrade first, then test the normal user flow.
- Find every place where Twig is installed or used.
- Upgrade Twig to 3.26.0 or a newer fixed release from the vendor.
- If you cannot upgrade right away, limit access to the affected feature until the update is done.
- Restart or redeploy the service if the product needs it after the update.
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Verify the fix
- Confirm the installed version is 3.26.0 or newer.
- Run a normal login, admin, and user flow to make sure the site still works.
- Check logs for new errors after the update.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-46640?
Symfony Twig versions listed as affected should be reviewed: Twig 3.15.0 before 3.26.0.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.