Thymeleaf: Improper recognition of unauthorized syntax patterns in sandboxed Thymeleaf expressions
Title source: cnaExploitation Summary
EIP tracks 2 public exploits for CVE-2026-41901. PoCs published by dwisiswant0, HORKimhab.
AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-41901, a critical SSTI vulnerability in Thymeleaf <= 3.1.4.RELEASE. The exploit leverages a case-sensitivity bypass in SpEL type reference detection to achieve remote code execution.
Description
Thymeleaf is a server-side Java template engine for web and standalone environments. Prior to 3.1.5.RELEASE, a security bypass vulnerability exists in the expression execution mechanisms of Thymeleaf. Although the library provides mechanisms to avoid the execution of potentially dangerous expressions in some specific sandboxed (restricted) contexts, it fails to properly neutralize specific constructs that allow this kind of expressions to be executed. If an application developer passes to the template engine unsanitized variables that contain such expressions, and these values are used in sandboxed contexts inside the templates, these expressions can be executed achieving Server-Side Template Injection (SSTI). This vulnerability is fixed in 3.1.5.RELEASE.
Exploits (2)
This repository contains a functional exploit for CVE-2026-41901, a critical SSTI vulnerability in Thymeleaf <= 3.1.4.RELEASE. The exploit leverages a case-sensitivity bypass in SpEL type reference detection to achieve remote code execution.
This repository contains a functional exploit for CVE-2026-41901, demonstrating remote command execution (RCE) in a Thymeleaf application via SpEL injection. The exploit includes a Docker-based lab setup and a script to execute arbitrary commands.
References (1)
Scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H