CVEvulnerability
CVE-2026-40477
9.0 CRITICAL
Official page ↗
- Status
- Modified
- Published
- 2026-04-17
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 9.0 CRITICAL — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- CVSS 3.1 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)
- 8.5 HIGH — CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
- Weaknesses
- CWE-1336, CWE-917
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.
Affected configurations
• thymeleaf thymeleaf (< 3.1.4)
Related
References
- https://github.com/thymeleaf/thymeleaf/security/advisories/GHSA-r4v4-5mwr-2fwr Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:21772 access.redhat.com
- https://access.redhat.com/security/cve/CVE-2026-40477 access.redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=2459344 bugzilla.redhat.com
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40477.json security.access.redhat.com