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 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.

Published: 2026-05-12 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-41901 is rated Moderate Risk (44.1/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.08%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-41901

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-13 — 0.08% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-41901

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.0 3.1 CRITICAL
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 6.0 [email protected]

Weakness enumeration for CVE-2026-41901

GitHub Security Advisory for CVE-2026-41901

GHSA-c9ph-gxww-7744 · Severity: critical · Ecosystem: maven — Sandboxed Thymeleaf expressions vulnerable to improper recognition of unauthorized syntax patterns

Affected software / configurations for CVE-2026-41901

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-41901

cvelogic Threat Intelligence