dbcve.org
TwigFramework / library · Symfony

CVE-2026-46634

CRITICAL · 9.8 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 3.26.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 5 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Twig is a template language for PHP. From 3.9.0 until 3.26.0, template_from_string() compiles an inner template under a synthesized __string_template__<hash> name that can fall outside a SourcePolicyInterface sandbox decision, allowing a sandboxed template that can call template_from_string and include to render an inner template without security policy enforcement. This issue is fixed in version 3.26.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Twig's template_from_string() function creates inner templates with a synthesized __string_template__<hash> name that bypasses SourcePolicyInterface sandbox decisions, allowing sandboxed templates to render content without security policy enforcement.

MitigationUpgrade Twig to version 3.26.0 or later. Avoid using template_from_string() in sandboxed templates until the upgrade is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TwigFramework / library
Affected:>= 3.9.0, < 3.26.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Twig version
    Run 'composer show symfony/twig-bridge' or check your composer.lock for the symfony/twig-bridge or symfony/twig-package version. Also check vendor/twig/twig/lib/Twig/Environment.php for the VERSION constant.
    Affected if The installed version is 3.9.0 or higher but lower than 3.26.0
  2. Verify Symfony Twig package in use
    Check if your project depends on 'symfony/twig-bridge' or 'twig/twig' by running 'composer show -t symfony/twig-bridge' and examining the dependency tree.
    Affected if The project uses symfony/twig-bridge or twig/twig within the affected version range
  3. Confirm SourcePolicyInterface sandbox is enabled
    Search your codebase for 'SourcePolicyInterface' or 'SandboxExtension' usage in configuration files (such as config/packages/twig.yaml) or template setup files.
    Affected if The application has sandbox policies enabled through SourcePolicyInterface or SandboxExtension
  4. Detect template_from_string usage in templates
    Search your Twig templates for calls to 'template_from_string' function using grep: grep -r 'template_from_string' your/templates/path/
    Affected if Templates contain calls to template_from_string() in sandboxed contexts
  5. Detect include usage in sandboxed contexts
    Search for 'include' calls within templates that are loaded through sandboxed contexts or within templates that use sandbox-aware includes.
    Affected if The application uses include in templates that are processed by the sandbox policy

You are affected if your Twig version is 3.9.0 or higher but lower than 3.26.0 AND you use the sandbox feature with templates containing template_from_string() or include statements that rely on sandbox enforcement.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.26.0 or later
Fixed in 3.26.0
Interim mitigation

Upgrade Twig to version 3.26.0 or later. Avoid using template_from_string() in sandboxed templates until the upgrade is applied.

Recommended fix High confidence

Twig 3.26.0 or later

  1. 1. Check the current Twig version in use by running `composer show twig/twig` or checking your composer.json
  2. 2. Update the Composer requirement for Twig to version 3.26.0 or later: `composer require twig/twig:^3.26.0` or manually update composer.json to `"twig/twig": "^3.26.0"`
  3. 3. Run `composer update twig/twig` to install the fixed version
  4. 4. Test the application, particularly any code using template_from_string() within sandboxed templates, to confirm the security policy is now properly enforced

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Twig Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-46634 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data