twig/twig security advisory

CVE-2026-46638: {% sandbox %}{% include %} skips checkSecurity() on cached templates (incomplete fix for CVE-2024-45411) in twig/twig

CVE-2026-46638 is a medium-severity security vulnerability in the PHP package twig/twig (CVSS 8.1), published 14 July 2026. It is fixed in 3.26.0; earlier versions are affected. Exploiting it needs a low-privilege user account.

medium 8.1 published 2026-07-14 · updated 2026-10-24

Affected versions: >= 1.0.0, < 3.26.0
Fixed in: 3.26.0
Newest release: 3.30.0
Severity: Medium · CVSS 8.1
Type: Security issue
CWE-693
Exploited in the wild: Not on the CISA KEV list
checked 2026-11-04

Is your twig/twig version affected?

Run composer show twig/twig in your project, then enter the version. We check it against this and every other known twig/twig advisory.

Who can exploit CVE-2026-46638

Access: A normal, low-privilege user account in the app.

CVSS vector (scored by NVD): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Your app is only exposed if it uses the affected part of twig/twig. The advisory below says which part that is. If you are not sure, upgrade anyway: it costs less than finding out.

How to fix CVE-2026-46638 in twig/twig

Find the installed version: composer show twig/twig. If you never required it yourself, composer why twig/twig shows which package pulls it in.
Update it: composer update twig/twig --with-all-dependencies. You need 3.26.0 or newer.
If Composer will not go that high, your composer.json constraint is holding it back. Widen it (for example "twig/twig": "^3.26.0" if you can take that version), or upgrade the package that requires it.
Run composer audit. It reads the same advisory data and should no longer list CVE-2026-46638.
Commit composer.lock and deploy it. On the server, run composer install --no-dev from the lock file, not composer update.

If you cannot upgrade yet

General hardening for this kind of issue while the upgrade waits. None of it replaces the fix.

If your app does not use the affected feature, note that in your audit, but still plan the upgrade.

The CVE-2026-46638 advisory

Twig is a template language for PHP. Prior to 3.26.0, {% sandbox %}{% include %} can include a template that was previously loaded outside the sandbox without re-invoking checkSecurity(), allowing the cached template to use tags, filters, and functions that should have been denied by SecurityPolicy::checkSecurity(). This issue is fixed in version 3.26.0.

Description from the CVE record, published by GitHub (the CVE Numbering Authority), via the NVD entry for CVE-2026-46638. Advisory title: “{% sandbox %}{% include %} skips checkSecurity() on cached templates (incomplete fix for CVE-2024-45411)”.

References

GitHub security advisory GHSA-7fxw-r6jv-74c8 github.com
Symfony security advisory symfony.com
Fix commit 819c6a8 github.com
Release v3.26.0 github.com

Other twig/twig advisories

Need help patching or upgrading? Laskyr does PHP and Laravel security fixes and upgrades. Tell us what you run and we reply with a plan and a price.

Ask about a fix

Where this data comes from

Affected and fixed versions: the Packagist security advisories API (GitHub Advisory Database and FriendsOfPHP), the same data composer audit uses. Synced 2026-11-03.
Description, score, weakness and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Exploited-in-the-wild status: the CISA Known Exploited Vulnerabilities catalog, checked 2026-11-04.
Compiled by Daniel Lasek at Laskyr from the sources above. The summary, “who can exploit it”, “how to fix it” and hardening sections are our plain-English reading of the record and are generated from it. The quoted description is the record's own text. Spot an error? Tell us.