dbcve.org
TwigFramework / library · Symfony

CVE-2026-48806

CRITICAL · 9.1 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 3.27.0 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. Prior to 3.27.0, ArrayExpression does not guard dynamic mapping keys that are coerced to strings, allowing PHP to invoke __toString() on a Stringable object used as a mapping key without calling SandboxExtension::ensureToStringAllowed(). This issue is fixed in version 3.27.0.

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 PHP template engine before 3.27.0 has a sandbox bypass in ArrayExpression where dynamic mapping keys coerced to strings can invoke __toString() on Stringable objects without calling SandboxExtension::ensureToStringAllowed(), potentially allowing arbitrary code execution in applications processing untrusted templates.

MitigationUpgrade Twig to version 3.27.0 or later to receive the security fix. If upgrade is not immediately possible, avoid processing untrusted templates or ensure strict sandboxing is enforced.

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:< 3.27.0

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
None

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

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 Twig installation
    Check your project's composer.json for 'twig/twig' or 'symfony/twig-bridge' in dependencies, or inspect the vendor/twig directory.
    Affected if Twig is installed and the version cannot be determined or is below 3.27.0
  2. Determine installed Twig version
    Run 'composer show twig/twig' or check the version field in composer.lock under twig/twig, or read the Version class in vendor/twig/twig/lib/Twig/Version.php
    Affected if The installed version is earlier than 3.27.0
  3. Verify untrusted template processing
    Review your application code for locations where user-supplied or external input is used as template content for Twig rendering (e.g., template strings from database, API input, or file uploads).
    Affected if Your application processes templates derived from untrusted sources without prior sanitization
  4. Check sandbox configuration
    Inspect your Twig Environment configuration for SandboxExtension setup. Look for code like Environment->addExtension(new SandboxExtension()) and whether isSandboxThemeSafe() or security policy settings are defined.
    Affected if The Twig sandbox is not enabled or the security policy does not restrict __toString() calls on dynamic array keys

You are affected if Twig version is below 3.27.0 and your application renders untrusted templates without an enforced sandbox policy that blocks __toString() invocations on Stringable objects in array keys.

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 3.27.0 or later
Fixed in 3.27.0
Interim mitigation

Upgrade Twig to version 3.27.0 or later to receive the security fix. If upgrade is not immediately possible, avoid processing untrusted templates or ensure strict sandboxing is enforced.

Recommended fix High confidence

Twig 3.27.0

  1. Identify the method of installing Twig in your project (e.g., Composer, PEAR, or bundled with a framework)
  2. If using Composer, run `composer require twig/twig:^3.27.0` or `composer update twig/twig` to upgrade to the fixed version
  3. If using a framework, check the framework's documentation for how to update its Twig dependency
  4. After upgrading, run your test suite to verify the application functions correctly
  5. Verify the installed version by running `composer show twig/twig` or checking your lock file

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

Fix this in Twig Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
14.0 hours of engineering $2,400
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,840.

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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-2026-48806 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