Advisory record · GHSA-r4v4-5mwr-2fwr

Improper restriction of the scope of accessible objects in Thymeleaf expressions

CVSS 9.1 CriticalCriticalEPSS 0.0085 · 58th percentile

Critical, because:

  • CVSS score 9.1: 9.0 or more.

How we decide what’s critical

Published by the GitHub Advisory Database at 15 Apr 2026, 19:46 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
org.thymeleaf:thymeleafMaven<3.1.4.RELEASE3.1.4.RELEASE
org.thymeleaf:thymeleaf-spring5Maven<3.1.4.RELEASE3.1.4.RELEASE
org.thymeleaf:thymeleaf-spring6Maven<3.1.4.RELEASE3.1.4.RELEASE
Identifiers
GHSA-r4v4-5mwr-2fwr · CVE-2026-40477
Weakness (CWE)
CWE-917 · CWE-1336
Published
15 Apr 2026
Updated
5 May 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Thymeleaf (org.thymeleaf:thymeleaf, thymeleaf-spring5 and thymeleaf-spring6) versions before 3.1.4.RELEASE are affected. An unauthenticated remote attacker can bypass the library's expression protections when an application passes unvalidated user input directly to the template engine, which allows server-side template injection. Upgrade to 3.1.4.RELEASE; the source lists no workaround other than avoiding passing unvalidated input to the template engine.

Written 3 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
9.1 Critical 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0085, the 58th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:20 UTC First seen by agentprime
  2. 31 Oct 2026, 14:20 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.