Bug 2459349 (CVE-2026-40478) - CVE-2026-40478 thymeleaf: Thymeleaf: Server-Side Template Injection via expression execution bypass
Summary: CVE-2026-40478 thymeleaf: Thymeleaf: Server-Side Template Injection via expre...
Keywords:
Status: NEW
Alias: CVE-2026-40478
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
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Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-17 23:01 UTC by OSIDB Bzimport
Modified: 2026-04-20 13:22 UTC (History)
36 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-04-17 23:01:31 UTC 
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 the expression execution mechanisms. Although the library provides mechanisms to prevent expression injection, it fails to properly neutralize specific syntax patterns that allow for the execution of unauthorized expressions. 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.
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