CVE intelligence and bounded remediation

CVE-2026-24425 — Symfony Twig security vulnerability

Critical CVSS 9.9

Twig versions 2.16.x and 3.9.0 through 3.25.x contain a sandbox bypass vulnerability when using a SourcePolicyInterface that allows attackers with template rendering capabilities to pass arbitrary PHP callables to sort, filter, map, and reduce filters. Attackers can exploit the runtime check that fails to use the current template source to bypass sandbox restrictions and execute arbitrary code when the sandbox is enabled through a source policy rather than globally.

Severity
Critical
CVSS
9.9 (3.1)
Published
2026-05-20
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-693

Affected products

  • symfony / twig

Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

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Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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