Bug 2459344 (CVE-2026-40477) - CVE-2026-40477 thymeleaf: Thymeleaf: Server-Side Template Injection via security bypass in expression execution
Summary: CVE-2026-40477 thymeleaf: Thymeleaf: Server-Side Template Injection via secur...
Keywords:
Status: NEW
Alias: CVE-2026-40477
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:
Whiteboard:
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:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)

Description OSIDB Bzimport 2026-04-17 23:01:15 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 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.
Note You need to log in before you can comment on or make changes to this bug.