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 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.
Metrics
CVSS 3.1 9.0/10
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| thymeleaf | thymeleaf | < 3.1.4.RELEASE |
| thymeleaf | org.thymeleaf:thymeleaf-spring5 | < 3.1.4.RELEASE |
| thymeleaf | org.thymeleaf:thymeleaf-spring6 | < 3.1.4.RELEASE |
| Red Hat | Red Hat OpenShift Dev Spaces 3.28 | — |
| Red Hat | Red Hat OpenShift Dev Spaces 3.28 | — |
| Red Hat | Red Hat build of Apache Camel for Spring Boot 4 | — |
| Red Hat | Red Hat build of Apache Camel for Spring Boot 4 | — |
| Red Hat | Red Hat Fuse 7 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 7 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 7 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 7 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — |
| Red Hat | Red Hat Single Sign-On 7 | — |
| Red Hat | Red Hat Single Sign-On 7 | — |
| Red Hat | Red Hat Single Sign-On 7 | — |
| Red Hat | Red Hat Single Sign-On 7 | — |
References
- https://github.com/thymeleaf/thymeleaf/security/advisories/GHSA-xjw8-8c5c-9r79Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:21772
- https://access.redhat.com/security/cve/CVE-2026-40478
- https://bugzilla.redhat.com/show_bug.cgi?id=2459349
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40478.json
Timeline
- Published
- Apr 17, 2026
- Last modified
- Oct 26, 2026
- NVD status
- Modified