CVE-2026-41901

Estado: AplazadaCrítica (9)—

Thymeleaf is a server-side Java template engine for web and standalone environments. Prior to 3.1.5.RELEASE, a security bypass vulnerability exists in the expression execution mechanisms of Thymeleaf. Although the library provides mechanisms to avoid the execution of potentially dangerous expressions in some specific sandboxed (restricted) contexts, it fails to properly neutralize specific constructs that allow this kind of expressions to be executed. If an application developer passes to the template engine unsanitized variables that contain such expressions, and these values are used in sandboxed contexts inside the templates, these expressions can be executed achieving Server-Side Template Injection (SSTI). This vulnerability is fixed in 3.1.5.RELEASE.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Puntuación base: 9

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.54%
Percentil entre todas las CVEs puntuadas: 44
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access85 %
Impacto principalT1059 Command and Scripting Interpreterexecution90 %

SSTI en Thymeleaf (acceso N, sin interacción) permite inyectar expresiones en contextos sandboxed, logrando ejecución de código en el servidor Java; posible escalada si el proceso tiene privilegios elevados.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account Management Vulnerability Scanning Restrict Web-Based Content Network Segmentation Limit Software Installation Limit Access to Resource Over Network

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Thymeleaf — Thymeleaf^AI

CWE

CWE-917, CWE-1336

Referencias

https://github.com/thymeleaf/thymeleaf/security/advisories/GHSA-c9ph-gxww-7744

JSON original (NVD)

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