CVE-2026-40477: fallo crítico en thymeleaf
Improper restriction of the scope of accessible objects in Thymeleaf expressions
Publicada el · Actualizada el
28Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 9.1epss 0.9%
probabilidad de explotación
0.9%top 42% de las CVE
explotación observada
noninguna fuente lo reporta
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Productos afectados
thymeleaf · org.thymeleaf:thymeleaf-spring5thymeleaf · org.thymeleaf:thymeleaf-spring6thymeleaf · thymeleafCVEs relacionadas — thymeleaf
En el mismo producto, de las más peligrosas a las menos.
Referencias
https://access.redhat.com/errata/RHSA-2026:21772https://access.redhat.com/security/cve/CVE-2026-40477https://bugzilla.redhat.com/show_bug.cgi?id=2459344https://github.com/thymeleaf/thymeleaf/security/advisories/GHSA-r4v4-5mwr-2fwrhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40477.json