dbcve.org
TwigFramework / library · Symfony

CVE-2026-49981

HIGH · 8.2 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 3.27.0 or later.
See remediation →
91/100
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, the per-template filter, tag, and function allow-list verdict is computed when a Template instance is constructed and can remain cached after sandbox state changes between renders, allowing a later sandboxed render to reuse a template that was originally checked with a different or empty policy. 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 · moderate confidence

Twig's sandbox security mechanism has a cache timing vulnerability where the allow-list verdict for filters, tags, and functions is computed at Template instance construction. This verdict persists in cache even when sandbox policy changes between renders, allowing a template originally checked with a permissive or empty policy to be reused during a later sandboxed render, bypassing security controls.

MitigationUpgrade Twig to version 3.27.0 or later to receive the fix; verify that sandbox policies are correctly enforced after upgrade.

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
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/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. Determine installed Twig version
    Run `composer show twig/twig` or check your composer.lock file for the twig/twig package version
    Affected if Version is below 3.27.0
  2. Identify if sandbox security is in use
    Search your codebase for `SandboxExtension`, `SandboxSecurityPolicy`, or `sandbox` in your Twig configuration files (such as config/packages/twig.yaml)
    Affected if Sandbox security policy is configured and enforced on templates
  3. Verify template caching is enabled
    Check if Twig cache is configured in your framework configuration (look for `cache: ~` or a cache directory path in twig.yaml, or inspect if compiled template files exist in var/cache)
    Affected if Template compilation caching is active and templates are being reused across requests
  4. Confirm policy changes between renders
    Review application code to determine if sandbox policies are dynamically modified or if different policies are applied to the same template across different request contexts
    Affected if Same templates may be rendered with different sandbox policies over time

You are affected if using Symfony Twig version below 3.27.0 with sandbox security enabled and template caching active, where sandbox policies can change between template renders.

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 fix; verify that sandbox policies are correctly enforced after upgrade.

Recommended fix High confidence

3.27.0

  1. Upgrade Twig to version 3.27.0 or later using your package manager (e.g., composer require twig/twig:^3.27.0 or composer update twig/twig)
  2. After upgrading, verify that your application functions correctly with the new Twig version
  3. If using a framework, ensure the framework's Twig integration is compatible with Twig 3.27.0

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
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.

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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-2026-49981 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