Skip to content
Fencer Vulns
critical 9.0

CVE-2026-41901 json

Thymeleaf: Improper recognition of unauthorized syntax patterns in sandboxed Thymeleaf expressions

published 2026-05-04 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-29872 , GHSA-c9ph-gxww-7744

cvss
9.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.thymeleaf:thymeleaf 3.1.5.RELEASE
  • maven org.thymeleaf:thymeleaf-spring5 3.1.5.RELEASE
  • maven org.thymeleaf:thymeleaf-spring6 3.1.5.RELEASE
  • org.thymeleaf thymeleaf 3.1.5.RELEASE
  • thymeleaf thymeleaf 3.1.5.RELEASE
  • org.thymeleaf thymeleaf-spring5 3.1.5.RELEASE
  • org.thymeleaf thymeleaf-spring6 3.1.5.RELEASE

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-41901 updated cvss 9.0

thymeleaf: Thymeleaf: Server-Side Template Injection (SSTI) via expression execution bypass

  • Red Hat Fuse 7 thymeleaf
    affected: no fix planned “Will not fix”
  • Red Hat Single Sign-On 7 thymeleaf
    affected: no fix available “Fix deferred”
  • Red Hat JBoss Enterprise Application Platform Expansion Pack thymeleaf
    not affected: component not present
  • Red Hat OpenShift Dev Spaces devspaces/openvsx-rhel9, devspaces/pluginregistry-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
GitHub 3.1 9.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven org.thymeleaf:thymeleaf
<3.1.5.RELEASE
3.1.5.RELEASE
maven org.thymeleaf:thymeleaf-spring5
<3.1.5.RELEASE
3.1.5.RELEASE
maven org.thymeleaf:thymeleaf-spring6
<3.1.5.RELEASE
3.1.5.RELEASE

Affected products

  • thymeleaf thymeleaf

Classification

Weakness
  • CWE-917 Improper Neutralization of Special Elements used in an Expression Language Statement
  • CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.