Sandbox escape via inherited Markup method exemption
Published Sep 4, 2026 · Updated Sep 8, 2026
Sandbox bypass in Twig before 3.27.0 allows remote attackers to call public methods on application-supplied Markup subclasses. SecurityPolicy::checkMethodAllowed() returns without consulting allowedMethods for every Twig\Markup instance, and nonfinal subclasses inherit that exemption. Reachability requires a sandboxed template to receive a Markup-derived object; the template author can then invoke any public method on that object, exposing data returned by those methods.
Summary
What happened
Sandbox bypass in Twig before 3.27.0 allows remote attackers to call public methods on application-supplied Markup subclasses. SecurityPolicy::checkMethodAllowed() returns without consulting allowedMethods for every Twig\Markup instance, and nonfinal subclasses inherit that exemption. Reachability requires a sandboxed template to receive a Markup-derived object; the template author can then invoke any public method on that object, exposing data returned by those methods.
The record
- CVE
- CVE-2026-46636
- Published
- Sep 4, 2026
- Updated
- Sep 8, 2026
- Vendor
- Twig
- Product
- Twig
- Classifications
- CWE-1336
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 1.0.0, < 3.27.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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