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.
CVE-2026-40912
“—” 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.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.2
- EG Score
- 8.2HIGHmedium confidence
- EG Risk
- 52EG 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, 2026StripPrefixRegex auth bypass via Path/RawPath desync · Advisory · traefik/traefik · GitHub
https://github.com/traefik/traefik/security/advisories/GHSA-6jwx-7vp4-9847Release v3.7.0-rc.2 · traefik/traefik · GitHub
https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2Release v3.6.14 · traefik/traefik · GitHub
https://github.com/traefik/traefik/releases/tag/v3.6.14Release v2.11.43 · traefik/traefik · GitHub
https://github.com/traefik/traefik/releases/tag/v2.11.43Vendor 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 / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | devspaces/traefik-rhel9:1779786779 | 2026-05-28 | redhat |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| github.com/traefik/traefik | — |
| — |
| github.com/traefik/traefik/v2 | — |
| — |
| github.com/traefik/traefik/v3 | — |
| — |
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.
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
- 2026-10-18 03:42 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-17 14:45 UTCEG score recompute
- 2026-10-17 14:45 UTCVendor advisory
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-13 15:24 UTCOSV refresh
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-12 16:09 UTCEG score recompute
- 2026-10-11 19:51 UTCEG score recompute
- 2026-10-11 17:04 UTCEG score recompute
- 2026-10-11 14:31 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
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- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.8% · 54th percentile
- 2026-09-23 06:45 UTCOSV refresh
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-04 01:16 UTCOSV refresh
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.8% · 53rd percentile
- 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-17 13:48 UTCEG score recompute
- 2026-08-17 13:48 UTCVendor advisory
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-16 05:21 UTCEG score recompute
- 2026-08-16 05:21 UTCVendor advisory
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-14 15:36 UTCVendor advisory
- 2026-08-14 03:49 UTCEG score recompute
- 2026-08-14 03:49 UTCVendor advisory
- 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-13 06:43 UTCVendor advisory
- 2026-08-12 17:27 UTCEG score recompute
- 2026-08-12 17:27 UTCVendor advisory
- 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-11 16:23 UTCEG score recompute
- 2026-08-11 16:23 UTCVendor advisory
- 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-11 01:51 UTCEG score recompute
- 2026-08-11 01:51 UTCVendor advisory
- 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-10 02:34 UTCVendor advisory
- 2026-08-09 14:47 UTCEG score recompute
- 2026-08-09 14:47 UTCVendor advisory
- 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-09 03:00 UTCEG score recompute
- 2026-08-09 03:00 UTCVendor advisory
- 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-08 02:15 UTCEG score recompute
- 2026-08-08 02:15 UTCVendor advisory
- 2026-08-07 14:29 UTCVendor advisory
- 2026-08-07 02:39 UTCEG score recompute
- 2026-08-07 02:39 UTCVendor advisory
- 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-06 10:25 UTCVendor advisory
- 2026-08-05 22:38 UTCEG score recompute
- 2026-08-05 22:38 UTCVendor advisory
- 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.8% · 52nd percentile
- 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.8% · 51st percentile
- 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.8% · 51st percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownGo:github.com/traefik/traefik/v3
Same vendor
10 shownredhat:RHSA-2026:21772
Frequently asked(5)
What is CVE-2026-40912?
When was the CVE record for CVE-2026-40912 published?
Is CVE-2026-40912 actively exploited?
What is the CVSS score of CVE-2026-40912?
How do I remediate CVE-2026-40912?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-40912
Is Your Infrastructure Affected by CVE-2026-40912?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.