CVE-2026-88011

HIGHNVD 8.18.1
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.1 under NVD CVSS v3. EPSS exploit probability: 0.4% (36th 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 — 3 sources updated this week

Also known asEUVD-2026-75584 (ENISA EUVD) · GHSA-rf44-j88r-hh8c (GitHub Security Advisories)Source: ENISA EUVD

8.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.56, and from 3.0.0 until 3.7.12, a client-supplied dot-form header such as X.Authenticated.User survives ForwardAuth replacement and underscoreHeadersStrategy because Go treats it as distinct from X-Authenticated-User while normalization-prone CGI, WSGI, PHP, and NGINX backends collapse both names. A backend can consequently consume the client value instead of the identity Traefik asserted, allowing identity spoofing for any header managed by Traefik. The aliasHeadersStrategy protection is disabled by default and must be configured as delete or reject. The mitigation is available in 2.11.56 and 3.7.12.

CVSS v3
8.1
EG Score
8.1HIGHmedium confidence
EG Risk
37
EG Risk 37/100

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)
Severity81% × 45%
Impact severity (EG Severity): CVSS 8.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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.
EPSS PROB
0.4%
EPSS %ILE
36th
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 (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.

EG Severity
8.1 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
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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

September 10, 2026

Last Modified

September 15, 2026

Advisory Details (5)

Auto-updated Sep 10, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

v3.7.12

Patch available: traefik/traefik v3.7.12

https://github.com/traefik/traefik/releases/tag/v3.7.12
GitHub release Patch Available

v2.11.56

Patch available: traefik/traefik v2.11.56

https://github.com/traefik/traefik/releases/tag/v2.11.56
GitHub commit

commit 0331801c7232 (traefik/traefik)

Fix landed in traefik/traefik commit 0331801c7232 — awaiting tagged release

https://github.com/traefik/traefik/commit/0331801c72329e0eaeb850e53ccce87c57fbecf8
GitHub pull request

Add an entry point option to handle request headers with aliasing names

Fix merged in traefik/traefik PR #13720 on 2026-08-24 — awaiting tagged release

https://github.com/traefik/traefik/pull/13720
GitHub advisoryMentions a patch (unverified)

ForwardAuth identity spoofing via dot-form header alias · Advisory · traefik/traefik · GitHub

https://github.com/traefik/traefik/security/advisories/GHSA-rf44-j88r-hh8c

Vendor Advisories for CVE-2026-88011(2)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
gogithub.com/traefik/traefik/v2 @ 2.11.56 (fixes < 2.11.56)—ghsa
gogithub.com/traefik/traefik/v3 @ 3.7.12 (fixes >= 3.0.0, < 3.7.12)—ghsa

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 on: no fix on record
—
github.com/traefik/traefik/v2—
  • every version up to 2.11.56: fixed in 2.11.56
—
github.com/traefik/traefik/v3—
  • 3.0.0 up to 3.7.12: fixed in 3.7.12
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 48× 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.

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. 1 repeat row among the latest 95 is merged into the row it repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-11-01 07:37 UTCGHSA enrichmentGHSA-rf44-j88r-hh8c · GitHub severity MODERATE
  3. 2026-11-01 07:37 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  7. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  8. 2026-10-27 21:15 UTCEG score recompute
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-25 13:53 UTCEG score recompute
  13. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  15. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  18. 2026-10-20 09:12 UTCEG score recompute
  19. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  20. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  21. 2026-10-18 03:03 UTCEG score recompute
  22. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  23. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  24. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  25. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
Show 69 more
  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  2. 2026-10-13 05:05 UTCEG score recompute
  3. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  4. 2026-10-12 14:49 UTCEG score recompute
  5. 2026-10-11 19:15 UTCEG score recompute
  6. 2026-10-11 16:32 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  8. 2026-10-11 13:49 UTCEG score recompute
  9. 2026-10-11 07:17 UTCEG score recompute
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  11. 2026-10-10 08:11 UTCEG score recompute
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  13. 2026-10-08 23:47 UTCEG score recompute
  14. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  15. 2026-10-08 08:40 UTCEG score recompute
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  17. 2026-10-06 21:53 UTCEG score recompute
  18. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  19. 2026-10-05 22:48 UTCEG score recompute
  20. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  21. 2026-10-04 23:24 UTCEG score recompute
  22. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  23. 2026-10-04 00:17 UTCEG score recompute
  24. 2026-10-03 00:11 UTCEG score recompute
  25. 2026-10-02 00:39 UTCEG score recompute
  26. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  27. 2026-10-01 01:32 UTCEG score recompute
  28. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  29. 2026-09-30 01:56 UTCEG score recompute
  30. 2026-09-29 06:36 UTCEG score recompute
  31. 2026-09-28 19:03 UTCEG score recompute
  32. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  33. 2026-09-27 19:56 UTCEG score recompute
  34. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  35. 2026-09-26 20:51 UTCEG score recompute
  36. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  37. 2026-09-26 09:13 UTCEG score recompute
  38. 2026-09-24 19:02 UTCEG score recompute
  39. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  40. 2026-09-23 19:56 UTCEG score recompute
  41. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  42. 2026-09-22 20:51 UTCEG score recompute
  43. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  44. 2026-09-21 21:43 UTCEG score recompute
  45. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  46. 2026-09-20 22:37 UTCEG score recompute
  47. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  48. 2026-09-19 23:31 UTCEG score recompute
  49. 2026-09-19 00:25 UTCEG score recompute
  50. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  51. 2026-09-18 01:20 UTCEG score recompute
  52. 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  53. 2026-09-16 14:41 UTCEG score recompute
  54. 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  55. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  56. 2026-09-15 15:02 UTCEG score recompute
  57. 2026-09-15 07:33 UTCEG score recompute
  58. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  59. 2026-09-14 20:00 UTCEG score recompute▲ 2.80
  60. 2026-09-14 19:59 UTCNVD updateCVSS v3 → 8.1 · severity → HIGH
  61. 2026-09-14 12:57 UTCEG score recompute
  62. 2026-09-13 16:48 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  63. 2026-09-12 16:26 UTCEG score recompute
  64. 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  65. 2026-09-11 18:13 UTCEG score recompute
  66. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  67. 2026-09-10 16:20 UTCEG score recompute
  68. 2026-09-10 15:40 UTCEG score recomputeFirst assessed: 5.3 MEDIUM
  69. 2026-09-10 15:39 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-88011?
CVE-2026-88011 is a high-severity vulnerability; its CVE record was published on September 10, 2026. Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.56, and from 3.0.0 until 3.7.12, a client-supplied dot-form header such as X.Authenticated.User survives ForwardAuth replacement and underscoreHeadersStrategy because Go treats it as distinct from X-Authenticated-User…
When was the CVE record for CVE-2026-88011 published?
The CVE record for CVE-2026-88011 was published on September 10, 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 September 15, 2026; the record at its source may have been updated since.
Is CVE-2026-88011 actively exploited?
CVE-2026-88011 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88011?
CVE-2026-88011 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-88011?
A fix for CVE-2026-88011 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-88011 are linked in the Vendor Advisories panel on this page.

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