dbcve.org
TwigFramework / library · Symfony

CVE-2026-46627

MEDIUM · 6.5 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 3.26.0 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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 3.26.0, the Twig sandbox does not prevent a template from consuming CPU, memory, or wall-clock time, even under the strictest allow-list, allowing untrusted templates to cause resource exhaustion. This issue is addressed in version 3.26.0 by documenting that the sandbox does not protect against resource exhaustion.

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 sandbox mode prior to 3.26.0 fails to protect against resource exhaustion attacks. Even with strict allow-list configurations, untrusted template execution can consume excessive CPU, memory, or wall-clock time, enabling denial-of-service attacks. The fix in 3.26.0 was documentation-only, clarifying that the sandbox does not provide resource exhaustion protection.

MitigationImplement external resource controls at the PHP runtime level (set_time_limit, memory_limit), web server level (request timeouts), or application level (template execution limits) when processing untrusted Twig templates.

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:< 3.26.0

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 'composer show twig/twig' to display the installed version number, or check your composer.lock file for the twig/twig or symfony/twig-bridge package version.
    Affected if The displayed version is lower than 3.26.0 (e.g., 3.25.0, 3.20.0, etc.)
  2. Confirm sandbox mode is in use
    Search your codebase for sandbox-related configuration: look for 'SandboxExtension', 'sandbox', or 'Twig\Extension\SandboxExtension' in configuration files (e.g., config/packages/twig.yaml), service definitions, or template initialization code.
    Affected if Sandbox mode is explicitly enabled or the SandboxExtension is registered in your Twig environment configuration.
  3. Determine if untrusted templates are processed
    Identify whether your application accepts Twig templates from external sources, user input, or stored templates that are not validated internally. Check for template storage in databases, file uploads, or API-driven template rendering.
    Affected if Your application processes Twig templates that originate from untrusted sources outside your controlled codebase.

You are affected if you are running any Twig version below 3.26.0 with sandbox mode enabled while processing untrusted templates, as the sandbox does not protect against resource exhaustion in these conditions.

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

Implement external resource controls at the PHP runtime level (set_time_limit, memory_limit), web server level (request timeouts), or application level (template execution limits) when processing untrusted Twig templates.

Recommended fix High confidence

Twig 3.26.0

  1. 1. Verify current Twig version by checking your composer.json or vendor directory
  2. 2. Run composer require twig/twig:^3.26.0 to upgrade to the fixed version
  3. 3. Review the Twig 3.26.0 release notes and documentation regarding sandbox limitations
  4. 4. Implement additional resource protection measures: configure PHP's max_execution_time, memory_limit, and consider using a process timeout mechanism for sandboxed template rendering
  5. 5. Test that untrusted templates cannot cause resource exhaustion with your new protections in place
Caveat Twig 3.26.0 may include other changes; review the changelog for any template syntax or API modifications

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
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2026-46627 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