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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

• CVE-2026-48808: 0.41% estimated exploitation activity in the next 30 days; percentile 35.02 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 needsissandboxed 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…

Published by the source

30 Jun 2026, 18:43 UTC

Last modified by the source

30 Jun 2026, 18:43 UTC

Source last checked

26 Oct 2026, 14:49 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h8vq-8gpg-mhcg

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-48808

Advisory: Twig: Sandbox property allowlist bypass via the `column` filter under `SourcePolicyInterface`
IDs: CVE-2026-48808, GHSA-h8vq-8gpg-mhcg
Record: https://patchnext.com/advisories/cve-2026-48808 (revision 1, source checked 26 Oct 2026, 14:49 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: twig/twig 3.27.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist twig/twig: affected <= 3.26.0; fixed in 3.27.0

## Suggested inspection (read-only)
- Packagist twig/twig: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on twig/twig.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-h8vq-8gpg-mhcg (GitHub-reviewed advisory GHSA-h8vq-8gpg-mhcg lists affected ranges: Packagist twig/twig >=0 <=3.26.0)

Commands are suggestions: review each one before running it.