CVE-2026-40478

CRITICALPre-NVD 9.09.0—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.0 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.0
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.0Exploit: NoneExposed: 0

A fix is available — apply it.

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 neutralize specific syntax patterns that allow for the execution of unauthorized expressions. If an application developer passes unvalidated user input directly to the template engine, an unauthenticated remote attacker can bypass the library's protections to achieve Server-Side Template Injection (SSTI). This issue has ben fixed in version 3.1.4.RELEASE.

CVSS v3
9.0
EG Score
9.0(medium)
EPSS
51.5%
KEV
Not listed

Published

April 17, 2026

Last Modified

June 30, 2026

Advisory Details (1)

Auto-updated May 2, 2026
Patch available. Sources: github.
github Patch Available

Improper neutralization of specific syntax patterns for unauthorized expressions in Thymeleaf · Advisory · thymeleaf/thymeleaf · GitHub

https://github.com/thymeleaf/thymeleaf/security/advisories/GHSA-xjw8-8c5c-9r79

Vendor Advisories for CVE-2026-40478(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatdevspaces/pluginregistry-rhel9:17793594232026-05-28redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 1 ecosystem)
Maven(3)
PackageVulnerable rangeFixed inDependents
org.thymeleaf:thymeleaf1.0.0 ... m1 (81 versions)3.1.4.RELEASE—
org.thymeleaf:thymeleaf-spring53.0.10.RELEASE ... 3.1.3.RELEASE (22 versions)3.1.4.RELEASE—
org.thymeleaf:thymeleaf-spring63.1.0.M1 ... 3.1.3.RELEASE (9 versions)3.1.4.RELEASE—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 42× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 149 total refreshes for this CVE.

  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-08 15:15 UTCEPSS rescore
  4. 2026-07-07 13:46 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 16:27 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-04 06:31 UTCEPSS rescore
  11. 2026-07-01 15:06 UTCEPSS rescore
  12. 2026-06-30 23:22 UTCEPSS rescore
  13. 2026-06-29 14:06 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-28 04:56 UTCEPSS rescore
  16. 2026-06-27 03:08 UTCEPSS rescore
  17. 2026-06-25 13:49 UTCEPSS rescore
  18. 2026-06-25 13:49 UTCEPSS rescore
  19. 2026-06-24 14:05 UTCEPSS rescore
  20. 2026-06-23 21:33 UTCEPSS rescore
  21. 2026-06-22 14:25 UTCEPSS rescore
  22. 2026-06-22 14:25 UTCEPSS rescore
  23. 2026-06-21 14:56 UTCEPSS rescore
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 01:59 UTCEPSS rescore
Show 75 more
  1. 2026-06-19 19:25 UTCEPSS rescore
  2. 2026-06-18 17:52 UTCEPSS rescore
  3. 2026-06-18 17:52 UTCEPSS rescore
  4. 2026-06-17 17:53 UTCEPSS rescore
  5. 2026-06-16 17:52 UTCEPSS rescore
  6. 2026-06-15 17:49 UTCEPSS rescore
  7. 2026-06-15 04:04 UTCEG score recompute
  8. 2026-06-15 04:04 UTCVendor advisory
  9. 2026-06-14 23:45 UTCEG score recompute
  10. 2026-06-14 23:45 UTCVendor advisory
  11. 2026-06-14 19:22 UTCEG score recompute
  12. 2026-06-14 19:22 UTCVendor advisory
  13. 2026-06-13 23:00 UTCEPSS rescore
  14. 2026-06-12 23:12 UTCEPSS rescore
  15. 2026-06-12 23:12 UTCEPSS rescore
  16. 2026-06-12 07:45 UTCEG score recompute
  17. 2026-06-12 07:45 UTCVendor advisory
  18. 2026-06-12 03:21 UTCEG score recompute
  19. 2026-06-12 03:21 UTCVendor advisory
  20. 2026-06-11 23:02 UTCEG score recompute
  21. 2026-06-11 23:02 UTCVendor advisory
  22. 2026-06-11 18:44 UTCEG score recompute
  23. 2026-06-11 18:44 UTCVendor advisory
  24. 2026-06-11 14:00 UTCEPSS rescore
  25. 2026-06-10 22:18 UTCEPSS rescore
  26. 2026-06-10 22:03 UTCEG score recompute
  27. 2026-06-10 22:03 UTCVendor advisory
  28. 2026-06-10 17:45 UTCEG score recompute
  29. 2026-06-10 17:45 UTCVendor advisory
  30. 2026-06-10 13:26 UTCEG score recompute
  31. 2026-06-10 13:26 UTCVendor advisory
  32. 2026-06-10 13:22 UTCEPSS rescore
  33. 2026-06-10 13:22 UTCEPSS rescore
  34. 2026-06-10 09:08 UTCEG score recompute
  35. 2026-06-10 09:08 UTCVendor advisory
  36. 2026-06-10 04:49 UTCEG score recompute
  37. 2026-06-10 04:49 UTCVendor advisory
  38. 2026-06-10 00:13 UTCEG score recompute
  39. 2026-06-10 00:13 UTCVendor advisory
  40. 2026-06-09 18:44 UTCEG score recompute
  41. 2026-06-09 18:44 UTCVendor advisory
  42. 2026-06-09 14:26 UTCEG score recompute
  43. 2026-06-09 14:26 UTCVendor advisory
  44. 2026-06-09 10:08 UTCEG score recompute
  45. 2026-06-09 10:08 UTCVendor advisory
  46. 2026-06-09 05:50 UTCEG score recompute
  47. 2026-06-09 05:50 UTCVendor advisory
  48. 2026-06-08 14:17 UTCEPSS rescore
  49. 2026-06-08 14:17 UTCEPSS rescore
  50. 2026-06-08 11:18 UTCEG score recompute
  51. 2026-06-08 11:18 UTCVendor advisory
  52. 2026-06-08 06:47 UTCEG score recompute
  53. 2026-06-08 06:47 UTCVendor advisory
  54. 2026-06-08 02:29 UTCEG score recompute
  55. 2026-06-08 02:29 UTCVendor advisory
  56. 2026-06-07 22:11 UTCEG score recompute
  57. 2026-06-07 22:11 UTCVendor advisory
  58. 2026-06-07 17:51 UTCEG score recompute
  59. 2026-06-07 17:51 UTCVendor advisory
  60. 2026-06-07 15:25 UTCEPSS rescore
  61. 2026-06-07 15:25 UTCEPSS rescore
  62. 2026-06-07 13:33 UTCEG score recompute
  63. 2026-06-07 13:33 UTCVendor advisory
  64. 2026-06-07 09:14 UTCEG score recompute
  65. 2026-06-07 09:14 UTCVendor advisory
  66. 2026-06-07 04:54 UTCEG score recompute
  67. 2026-06-07 04:54 UTCVendor advisory
  68. 2026-06-06 13:47 UTCEPSS rescore
  69. 2026-06-06 13:47 UTCEPSS rescore
  70. 2026-06-06 06:28 UTCEG score recompute
  71. 2026-06-06 06:28 UTCVendor advisory
  72. 2026-06-06 01:12 UTCEG score recompute
  73. 2026-06-06 01:12 UTCVendor advisory
  74. 2026-06-05 22:47 UTCEPSS rescore
  75. 2026-06-05 12:55 UTCEG score recompute

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-40478?
CVE-2026-40478 is a critical vulnerability published on April 17, 2026. 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…
When was CVE-2026-40478 disclosed?
CVE-2026-40478 was first published in the National Vulnerability Database on April 17, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40478 actively exploited?
CVE-2026-40478 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40478?
CVE-2026-40478 has a CVSS v3 base score of 9.0 (NVD).
How do I remediate CVE-2026-40478?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40478, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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