Thymeleaf is a server-side Java template engine for web and standalone environments. Versions 3.1.3.RELEASE and prior contain a security bypass vulnerability in the expression execution mechanisms. Although the library provides mechanisms to prevent expression injection, it fails to properly restrict the scope of accessible objects, allowing specific potentially sensitive objects to be reached from within a template. If an application developer passes unvalidated user input directly to the template engine, an unauthenticated remote attacker can bypass the library's protections to achieve Server-Side Template Injection (SSTI). This issue has ben fixed in version 3.1.4.RELEASE.
History

Mon, 20 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Thymeleaf
Thymeleaf org.thymeleaf:thymeleaf-spring5
Thymeleaf org.thymeleaf:thymeleaf-spring6
Thymeleaf thymeleaf
Vendors & Products Thymeleaf
Thymeleaf org.thymeleaf:thymeleaf-spring5
Thymeleaf org.thymeleaf:thymeleaf-spring6
Thymeleaf thymeleaf

Mon, 20 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 17 Apr 2026 22:15:00 +0000

Type Values Removed Values Added
Description Thymeleaf is a server-side Java template engine for web and standalone environments. Versions 3.1.3.RELEASE and prior contain a security bypass vulnerability in the expression execution mechanisms. Although the library provides mechanisms to prevent expression injection, it fails to properly restrict the scope of accessible objects, allowing specific potentially sensitive objects to be reached from within a template. If an application developer passes unvalidated user input directly to the template engine, an unauthenticated remote attacker can bypass the library's protections to achieve Server-Side Template Injection (SSTI). This issue has ben fixed in version 3.1.4.RELEASE.
Title Improper restriction of the scope of accessible objects in Thymeleaf expressions
Weaknesses CWE-1336
CWE-917
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-20T13:36:06.261Z

Reserved: 2026-04-13T19:50:42.113Z

Link: CVE-2026-40477

cve-icon Vulnrichment

Updated: 2026-04-20T13:32:39.391Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-17T22:16:33.500

Modified: 2026-04-20T19:03:07.607

Link: CVE-2026-40477

cve-icon Redhat

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