CVE-2026-40912

HIGHNVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 67% 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
Trending — 3 sources updated this week
8.2
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.2Exploit: NoneExposed: 0

A fix is available — apply it.

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

CVSS v3
8.2
EG Score
8.2(medium)
EPSS
51.3%
KEV
Not listed

Published

April 30, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Apr 30, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

StripPrefixRegex auth bypass via Path/RawPath desync · Advisory · traefik/traefik · GitHub

https://github.com/traefik/traefik/security/advisories/GHSA-6jwx-7vp4-9847
generic

Release v3.7.0-rc.2 · traefik/traefik · GitHub

https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2
generic

Release v3.6.14 · traefik/traefik · GitHub

https://github.com/traefik/traefik/releases/tag/v3.6.14
generic

Release v2.11.43 · traefik/traefik · GitHub

https://github.com/traefik/traefik/releases/tag/v2.11.43

Vendor Advisories for CVE-2026-40912(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/traefik-rhel9:17797867792026-05-28redhat

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)
Go(3)
PackageVulnerable rangeFixed inDependents
github.com/traefik/traefik———
github.com/traefik/traefik/v2—2.11.43—
github.com/traefik/traefik/v3—3.6.14—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 39× 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 131 total refreshes for this CVE.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:25 UTCNVD updateCVSS v3 → 8.2
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-15 01:21 UTCMITRE cvelistV5CVSS v3 → 8.6
  6. 2026-07-13 22:30 UTCEPSS rescore
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-13 06:13 UTCEPSS rescore
  9. 2026-07-12 05:46 UTCEPSS rescore
  10. 2026-07-11 08:27 UTCEPSS rescore
  11. 2026-07-09 19:10 UTCEPSS rescore
  12. 2026-07-08 15:15 UTCEPSS rescore
  13. 2026-07-07 13:46 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-06 02:23 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-01 15:06 UTCEPSS rescore
  21. 2026-06-30 23:22 UTCEPSS rescore
  22. 2026-06-29 14:06 UTCEPSS rescore
  23. 2026-06-28 14:07 UTCEPSS rescore
  24. 2026-06-28 04:56 UTCEPSS rescore
  25. 2026-06-27 03:08 UTCEPSS rescore
Show 75 more
  1. 2026-06-25 13:49 UTCEPSS rescore
  2. 2026-06-25 13:49 UTCEPSS rescore
  3. 2026-06-24 14:05 UTCEPSS rescore
  4. 2026-06-23 21:33 UTCEPSS rescore
  5. 2026-06-22 14:25 UTCEPSS rescore
  6. 2026-06-22 14:25 UTCEPSS rescore
  7. 2026-06-21 14:56 UTCEPSS rescore
  8. 2026-06-21 14:56 UTCEPSS rescore
  9. 2026-06-21 01:59 UTCEPSS rescore
  10. 2026-06-19 19:25 UTCEPSS rescore
  11. 2026-06-18 17:52 UTCEPSS rescore
  12. 2026-06-18 17:52 UTCEPSS rescore
  13. 2026-06-17 17:53 UTCEPSS rescore
  14. 2026-06-16 17:52 UTCEPSS rescore
  15. 2026-06-15 17:49 UTCEPSS rescore
  16. 2026-06-14 21:02 UTCEG score recompute
  17. 2026-06-14 21:02 UTCVendor advisory
  18. 2026-06-14 09:15 UTCEG score recompute
  19. 2026-06-14 09:15 UTCVendor advisory
  20. 2026-06-13 23:00 UTCEPSS rescore
  21. 2026-06-12 23:12 UTCEPSS rescore
  22. 2026-06-12 23:12 UTCEPSS rescore
  23. 2026-06-12 11:40 UTCEG score recompute
  24. 2026-06-12 11:40 UTCVendor advisory
  25. 2026-06-11 23:18 UTCEG score recompute
  26. 2026-06-11 23:18 UTCVendor advisory
  27. 2026-06-11 14:00 UTCEPSS rescore
  28. 2026-06-11 11:32 UTCEG score recompute
  29. 2026-06-11 11:32 UTCVendor advisory
  30. 2026-06-10 23:02 UTCEG score recompute
  31. 2026-06-10 23:02 UTCVendor advisory
  32. 2026-06-10 22:18 UTCEPSS rescore
  33. 2026-06-10 13:22 UTCEPSS rescore
  34. 2026-06-10 13:22 UTCEPSS rescore
  35. 2026-06-10 11:15 UTCEG score recompute
  36. 2026-06-10 11:15 UTCVendor advisory
  37. 2026-06-09 23:28 UTCEG score recompute
  38. 2026-06-09 23:28 UTCVendor advisory
  39. 2026-06-09 11:26 UTCEG score recompute
  40. 2026-06-09 11:26 UTCVendor advisory
  41. 2026-06-08 23:39 UTCEG score recompute
  42. 2026-06-08 23:39 UTCVendor advisory
  43. 2026-06-08 14:17 UTCEPSS rescore
  44. 2026-06-08 14:17 UTCEPSS rescore
  45. 2026-06-08 08:57 UTCEG score recompute
  46. 2026-06-08 08:57 UTCVendor advisory
  47. 2026-06-07 21:10 UTCEG score recompute
  48. 2026-06-07 21:10 UTCVendor advisory
  49. 2026-06-07 15:25 UTCEPSS rescore
  50. 2026-06-07 15:25 UTCEPSS rescore
  51. 2026-06-07 09:23 UTCEG score recompute
  52. 2026-06-07 09:23 UTCVendor advisory
  53. 2026-06-06 21:35 UTCEG score recompute
  54. 2026-06-06 21:35 UTCVendor advisory
  55. 2026-06-06 13:47 UTCEPSS rescore
  56. 2026-06-06 13:47 UTCEPSS rescore
  57. 2026-06-06 09:24 UTCEG score recompute
  58. 2026-06-06 09:24 UTCVendor advisory
  59. 2026-06-05 22:47 UTCEPSS rescore
  60. 2026-06-05 21:37 UTCEG score recompute
  61. 2026-06-05 21:37 UTCVendor advisory
  62. 2026-06-05 09:50 UTCEG score recompute
  63. 2026-06-05 09:50 UTCVendor advisory
  64. 2026-06-05 06:10 UTCEPSS rescore
  65. 2026-06-05 06:10 UTCEPSS rescore
  66. 2026-06-04 21:39 UTCEG score recompute
  67. 2026-06-04 21:39 UTCVendor advisory
  68. 2026-06-04 13:12 UTCEPSS rescore
  69. 2026-06-04 13:12 UTCEPSS rescore
  70. 2026-06-04 09:51 UTCEG score recompute
  71. 2026-06-04 09:51 UTCVendor advisory
  72. 2026-06-03 22:03 UTCEG score recompute
  73. 2026-06-03 22:03 UTCVendor advisory
  74. 2026-06-03 10:08 UTCEG score recompute
  75. 2026-06-03 10:08 UTCVendor advisory

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-40912?
CVE-2026-40912 is a high vulnerability published on April 30, 2026. Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches…
When was CVE-2026-40912 disclosed?
CVE-2026-40912 was first published in the National Vulnerability Database on April 30, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40912 actively exploited?
CVE-2026-40912 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40912?
CVE-2026-40912 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-40912?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40912, 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.

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