CVE-2026-46634

描述

### Description When the sandbox is enabled selectively via `SourcePolicyInterface` (and not globally), a sandboxed template that is allowed to call `template_from_string` and `include` can render an arbitrary inner template with no security policy enforcement. `Environment::createTemplate()` compiles the inner string under a synthesized name (`__string_template__<hash>`), so a name/path-based `SourcePolicy` returns `false` for it, and the inner template's `checkSecurity()` becomes a no-op. From a template the integrator believes is sandboxed, an attacker can use any tag/filter/function (including `constant()` to read secrets, or `|map("system")` to execute shell commands). ### Resolution This is a configuration trap rather than a code bug: there is no legitimate use case for exposing `template_from_string` to untrusted template authors, and propagating the parent sandbox state through `template_from_string` would require invasive changes to `SourcePolicyInterface` semantics with their own risks. Starting with Twig 3.26.0, the documentation and the PHPDoc of `StringLoaderExtension::templateFromString()` explicitly warn against allowing `template_from_string` in a sandboxed environment (i.e. listing it in a `SecurityPolicy` allowed-functions list). Integrators using a `SourcePolicyInterface` MUST NOT allow `template_from_string` in their allowed functions; the safest option is not to register `StringLoaderExtension` at all when a sandbox is in use. ### Credits Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue.

如何修補 CVE-2026-46634

要修補 CVE-2026-46634,請將受影響套件升級到下列已修補版本。

• —升級至 3.27.0-0+deb13u1 或更新版本

CVE-2026-46634 正在被利用嗎?

低 — EPSS 為 0.4%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• from 0, < 3.27.0-0+deb13u1