Twig: Sandbox `__toString()` policy bypass via `Traversable` in `join` and `replace` filters

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0037, the 30th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 27 May 2026, 13:13 UTC Published by the maintainers as a GitHub repository advisory
2. 31 Oct 2026, 13:57 UTC First seen by agentprime
3. 31 Oct 2026, 13:57 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-8x9c-rmqh-456c
• OSV: GHSA-8x9c-rmqh-456c
• github.com/twigphp/Twig/security/advisories/GHSA-8x9c-rmqh-456c
• github.com/FriendsOfPHP/security-advisories/blob/master/twig/twig/CVE-2026-48807.yaml
• github.com/twigphp/Twig
• github.com/twigphp/Twig/releases/tag/v3.27.0
• symfony.com/blog/cve-2026-48807-sandbox-tostring-policy-bypass-via-traversable-in-join-replace-and-in-not-in-operators

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.