RHLW-2026-E0E5640C50CEEA84 Lightwell Security Advisory: thymeleaf 3.0.15.RELEASE-rhlw-00009

Red Hat Lightwell has released org.thymeleaf:thymeleaf 3.0.15.RELEASE-rhlw-00009 with backported fixes for CVE-2026-40477, CVE-2026-40478, and CVE-2026-41901. CVE-2026-40477: Improper restriction of the scope of accessible objects in Thymeleaf expressions CVE-2026-40478: Improper neutralization o...

CVE-2026-41901 Thymeleaf: Improper recognition of unauthorized syntax patterns in sandboxed Thymeleaf expressions

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...

CVE-2026-40478

A flaw was found in Thymeleaf, a server-side Java template engine. An unauthenticated remote attacker can exploit this vulnerability by providing unvalidated user input to the template engine. This bypasses existing security mechanisms, allowing for the execution of unauthorized expressions and...

CVE-2026-40478

CVE-2026-40478 affects the Thymeleaf Java template engine (versions up to 3.1.3.RELEASE). A security bypass allows unauthenticated SSTI by passing unvalidated input to the expression evaluation mechanism; this is fixed in 3.1.4.RELEASE. Connected sources consistently state the root cause as impro...

CVE-2026-40478 Improper neutralization of specific syntax patterns for unauthorized expressions in Thymeleaf

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...