CVE-2026-40477

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.9%, top 45% 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: cna:github_m, epss
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: None knownExposed: 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 expression execution mechanisms. Although the library provides mechanisms to prevent expression injection, it fails to properly restrict the scope of accessible objects, allowing specific potentially sensitive objects to be reached from within a template. 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
9.1
EG Score
9.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
55%
KEV
Not listed

Published

April 17, 2026

Last Modified

August 17, 2026

Advisory Details (1)

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

Improper restriction of the scope of accessible objects in Thymeleaf expressions · Advisory · thymeleaf/thymeleaf · GitHub

https://github.com/thymeleaf/thymeleaf/security/advisories/GHSA-r4v4-5mwr-2fwr

Vendor Advisories for CVE-2026-40477(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 5× in last 7d / 94× 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 232 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-19 17:03 UTCEPSS rescore
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-17 12:12 UTCEG score recompute▲ 0.10
  9. 2026-08-17 12:12 UTCVendor advisory
  10. 2026-08-17 12:11 UTCMITRE cvelistV5CVSS v3 → 9.1
  11. 2026-08-16 14:56 UTCEPSS rescore
  12. 2026-08-16 10:28 UTCVendor advisory
  13. 2026-08-16 06:29 UTCEG score recompute
  14. 2026-08-16 06:29 UTCVendor advisory
  15. 2026-08-16 02:14 UTCEPSS rescore
  16. 2026-08-15 02:26 UTCEG score recompute
  17. 2026-08-15 02:26 UTCVendor advisory
  18. 2026-08-15 01:30 UTCEPSS rescore
  19. 2026-08-14 22:20 UTCVendor advisory
  20. 2026-08-14 18:07 UTCVendor advisory
  21. 2026-08-14 12:34 UTCVendor advisory
  22. 2026-08-14 08:35 UTCVendor advisory
  23. 2026-08-14 04:36 UTCEG score recompute
  24. 2026-08-14 04:36 UTCVendor advisory
  25. 2026-08-13 22:00 UTCEPSS rescore
Show 75 more
  1. 2026-08-13 08:51 UTCVendor advisory
  2. 2026-08-13 02:44 UTCVendor advisory
  3. 2026-08-12 22:46 UTCVendor advisory
  4. 2026-08-12 18:47 UTCEG score recompute
  5. 2026-08-12 18:47 UTCVendor advisory
  6. 2026-08-12 13:51 UTCEPSS rescore
  7. 2026-08-12 00:54 UTCVendor advisory
  8. 2026-08-11 20:55 UTCVendor advisory
  9. 2026-08-11 16:57 UTCEG score recompute
  10. 2026-08-11 16:57 UTCVendor advisory
  11. 2026-08-11 13:43 UTCEPSS rescore
  12. 2026-08-11 06:32 UTCVendor advisory
  13. 2026-08-11 02:33 UTCEG score recompute
  14. 2026-08-11 02:33 UTCVendor advisory
  15. 2026-08-11 00:00 UTCEPSS rescore
  16. 2026-08-10 12:50 UTCVendor advisory
  17. 2026-08-10 08:38 UTCVendor advisory
  18. 2026-08-10 04:40 UTCVendor advisory
  19. 2026-08-10 00:41 UTCVendor advisory
  20. 2026-08-09 20:42 UTCVendor advisory
  21. 2026-08-09 16:43 UTCEG score recompute
  22. 2026-08-09 16:43 UTCVendor advisory
  23. 2026-08-09 13:46 UTCEPSS rescore
  24. 2026-08-09 12:44 UTCVendor advisory
  25. 2026-08-09 07:51 UTCVendor advisory
  26. 2026-08-09 03:52 UTCEG score recompute
  27. 2026-08-09 03:52 UTCVendor advisory
  28. 2026-08-08 16:37 UTCEPSS rescore
  29. 2026-08-08 09:14 UTCVendor advisory
  30. 2026-08-08 05:15 UTCVendor advisory
  31. 2026-08-08 01:16 UTCVendor advisory
  32. 2026-08-07 21:17 UTCVendor advisory
  33. 2026-08-07 17:17 UTCEG score recompute
  34. 2026-08-07 17:17 UTCVendor advisory
  35. 2026-08-07 13:19 UTCVendor advisory
  36. 2026-08-06 21:29 UTCVendor advisory
  37. 2026-08-06 17:28 UTCEG score recompute
  38. 2026-08-06 17:28 UTCVendor advisory
  39. 2026-08-06 13:46 UTCEPSS rescore
  40. 2026-08-06 11:59 UTCVendor advisory
  41. 2026-08-06 07:15 UTCVendor advisory
  42. 2026-08-06 03:16 UTCVendor advisory
  43. 2026-08-05 23:18 UTCEG score recompute
  44. 2026-08-05 23:18 UTCVendor advisory
  45. 2026-08-05 19:17 UTCEPSS rescore
  46. 2026-08-04 15:10 UTCEPSS rescore
  47. 2026-08-04 13:27 UTCEG score recompute▼ 0.10
  48. 2026-08-04 13:27 UTCVendor advisory
  49. 2026-08-04 13:26 UTCNVD updateCVSS v3 → 9
  50. 2026-08-04 12:34 UTCEG score recompute▲ 0.10
  51. 2026-08-04 12:34 UTCVendor advisory
  52. 2026-08-04 12:33 UTCMITRE cvelistV5CVSS v3 → 9.1
  53. 2026-08-04 10:38 UTCEPSS rescore
  54. 2026-08-04 05:35 UTCVendor advisory
  55. 2026-08-04 01:28 UTCVendor advisory
  56. 2026-08-03 21:29 UTCEG score recompute
  57. 2026-08-03 21:29 UTCVendor advisory
  58. 2026-08-03 10:36 UTCEPSS rescore
  59. 2026-08-03 00:57 UTCVendor advisory
  60. 2026-08-02 20:58 UTCVendor advisory
  61. 2026-08-02 16:59 UTCVendor advisory
  62. 2026-08-02 13:00 UTCEG score recompute
  63. 2026-08-02 13:00 UTCVendor advisory
  64. 2026-08-02 02:27 UTCEPSS rescore
  65. 2026-08-01 04:16 UTCEPSS rescore
  66. 2026-07-30 16:28 UTCEPSS rescore
  67. 2026-07-30 01:30 UTCEPSS rescore
  68. 2026-07-28 15:36 UTCEPSS rescore
  69. 2026-07-27 14:13 UTCEPSS rescore
  70. 2026-07-26 14:54 UTCEPSS rescore
  71. 2026-07-26 14:54 UTCEPSS rescore
  72. 2026-07-25 14:18 UTCEPSS rescore
  73. 2026-07-25 14:18 UTCEPSS rescore
  74. 2026-07-24 14:17 UTCEPSS rescore
  75. 2026-07-24 14:17 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-40477?
CVE-2026-40477 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 expression execution mechanisms. Although the library provides mechanisms to prevent expression injection, it fails to properly…
When was CVE-2026-40477 disclosed?
CVE-2026-40477 was first published in the National Vulnerability Database on April 17, 2026, with the most recent update on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40477 actively exploited?
CVE-2026-40477 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 44.5% of all scored CVEs.
What is the CVSS score of CVE-2026-40477?
CVE-2026-40477 has a CVSS v4.0 base score of 9.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-40477?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40477, 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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