Allocation of Resources Without Limits or Throttling in Twig - CVE-2026-46629
Published: May 20, 2026
Vulnerability identifier: #VU131994
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-46629
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Symfony
Affected software:
Twig
Twig
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to allocation of resources without limits or throttling in IntlExtension formatter memoization when processing template-controlled formatter arguments. A remote attacker can supply many distinct locale, pattern, or formatting argument values to cause a denial of service.
On long-running runtimes where the Twig environment persists across requests, the cache can accumulate across requests, and the allocated ICU backing buffers are not bounded by PHP memory_limit.
How to mitigate CVE-2026-46629
Install security update from vendor's website.