CVE-2026-40912

HIGHNVD 8.28.2
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This high-severity CVE scores 8.2 under NVD CVSS v3. EPSS exploit probability: 0.7% (53rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 4 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 8.2Exploit: None knownExposed services: Not assessed

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
8.2HIGHmedium confidence
EG Risk
52
EG Risk 52/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity82% × 45%
Impact severity (EG Severity): CVSS 8.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.7% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
53rd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.2): severity, escalated by confirmed exploitation. This CVE's 8.2 is its impact severity (EG Severity), not escalated.

EG Severity
8.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

April 30, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Apr 30, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

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

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

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

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

Release v3.6.14 · traefik/traefik · GitHub

https://github.com/traefik/traefik/releases/tag/v3.6.14
Web page

Release v2.11.43 · traefik/traefik · GitHub

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

Vendor Advisories for CVE-2026-40912(2)

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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
github.com/traefik/traefik—
  • every version through 1.7.34: no fix on record
  • every version on: no fix on record
—
github.com/traefik/traefik/v2—
  • every version up to 2.11.43: fixed in 2.11.43
—
github.com/traefik/traefik/v3—
  • 3.7.0-ea.1 up to 3.7.0-rc.2: fixed in 3.7.0-rc.2
  • 3.0.0-beta1 up to 3.6.14: fixed in 3.6.14
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 31× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 231 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 131 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  2. 2026-10-18 03:42 UTCEG score recompute
  3. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-10-17 14:45 UTCEG score recompute
  5. 2026-10-17 14:45 UTCVendor advisory
  6. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  7. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  8. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  9. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  10. 2026-10-13 15:24 UTCOSV refresh
  11. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  12. 2026-10-12 16:09 UTCEG score recompute
  13. 2026-10-11 19:51 UTCEG score recompute
  14. 2026-10-11 17:04 UTCEG score recompute
  15. 2026-10-11 14:31 UTCEG score recompute
  16. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  17. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  18. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  19. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  23. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  24. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
Show 75 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  2. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  3. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.8% · 54th percentile
  5. 2026-09-23 06:45 UTCOSV refresh
  6. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  7. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  8. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  9. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  10. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  11. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  12. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  13. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  14. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  15. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  16. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  17. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  18. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  19. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  20. 2026-09-04 01:16 UTCOSV refresh
  21. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  22. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
  23. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  24. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  25. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  26. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  27. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  28. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  29. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  30. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  31. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  32. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  33. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  34. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  35. 2026-08-17 13:48 UTCEG score recompute
  36. 2026-08-17 13:48 UTCVendor advisory
  37. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  38. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  39. 2026-08-16 05:21 UTCEG score recompute
  40. 2026-08-16 05:21 UTCVendor advisory
  41. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  42. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  43. 2026-08-14 15:36 UTCVendor advisory
  44. 2026-08-14 03:49 UTCEG score recompute
  45. 2026-08-14 03:49 UTCVendor advisory
  46. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  47. 2026-08-13 06:43 UTCVendor advisory
  48. 2026-08-12 17:27 UTCEG score recompute
  49. 2026-08-12 17:27 UTCVendor advisory
  50. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  51. 2026-08-11 16:23 UTCEG score recompute
  52. 2026-08-11 16:23 UTCVendor advisory
  53. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  54. 2026-08-11 01:51 UTCEG score recompute
  55. 2026-08-11 01:51 UTCVendor advisory
  56. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  57. 2026-08-10 02:34 UTCVendor advisory
  58. 2026-08-09 14:47 UTCEG score recompute
  59. 2026-08-09 14:47 UTCVendor advisory
  60. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  61. 2026-08-09 03:00 UTCEG score recompute
  62. 2026-08-09 03:00 UTCVendor advisory
  63. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  64. 2026-08-08 02:15 UTCEG score recompute
  65. 2026-08-08 02:15 UTCVendor advisory
  66. 2026-08-07 14:29 UTCVendor advisory
  67. 2026-08-07 02:39 UTCEG score recompute
  68. 2026-08-07 02:39 UTCVendor advisory
  69. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  70. 2026-08-06 10:25 UTCVendor advisory
  71. 2026-08-05 22:38 UTCEG score recompute
  72. 2026-08-05 22:38 UTCVendor advisory
  73. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
  74. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.8% · 51st percentile
  75. 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.8% · 51st percentile

Frequently asked(5)

What is CVE-2026-40912?
CVE-2026-40912 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-40912 published?
The CVE record for CVE-2026-40912 was published on April 30, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 15, 2026; the record at its source may have been updated since.
Is CVE-2026-40912 actively exploited?
CVE-2026-40912 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (53rd percentile of EPSS-scored CVEs).
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?
A fix for CVE-2026-40912 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40912 are linked in the Vendor Advisories panel on this page.

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