medium

CVE-2026-48808

Packagist · twig/twig

Summary

Twig: Sandbox property allowlist bypass via the `column` filter under `SourcePolicyInterface`

Severity
medium
EPSS
0.4% (p34)
CWE
CWE-693, CWE-863
Also known as
GHSA-h8vq-8gpg-mhcg
Published
2026-06-30
Updated
2026-06-30

Advisory details

Description

This is a residual bypass of CVE-2026-46635 / GHSA-vcc8-phrv-43wj that only affects sandboxing enabled through SourcePolicyInterface (and not the regular global sandbox mode).

CoreExtension::column() receives the active sandbox state via the needs_is_sandboxed channel as a boolean $isSandboxed, but then routes the per-element property reads through SandboxExtension::checkPropertyAllowed() without forwarding the current Source. SandboxExtension::checkPropertyAllowed() re-evaluates isSandboxed($source) internally; with $source = null the SourcePolicyInterface-driven decision is lost, the method short-circuits to "not sandboxed", and the property allowlist is never consulted.

A template author whose sandbox is gated by a SourcePolicyInterface and who has column on their allowedFilters list can therefore read any public or magic property of any object reachable in the render context, regardless of SecurityPolicy::$allowedProperties. Direct attribute access to the same property is blocked, and the same payload is also blocked under global sandbox mode, which makes this a clear policy enforcement gap rather than a configuration issue.

Resolution

CoreExtension::column() no longer goes through the SandboxExtension wrapper for the property check. It calls the security policy directly: the per-source decision is already captured by the $isSandboxed boolean computed at the call site, so the property allowlist is enforced consistently for both global and source-policy sandboxing.

Credits

Twig would like to thank Vincent55 Yang for reporting the issue and Fabien Potencier for providing the fix.

References

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Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.