CVE-2026-54763

CRITICALNVD 10.010.0
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 10.0 under NVD CVSS v3. EPSS exploit probability: 0.2% (15th 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

Also known asEUVD-2026-41940 (ENISA EUVD) · GHSA-x677-9fxg-v5c5 (GitHub Security Advisories)Source: ENISA EUVD

10.0EG
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: 0.2%CVSS: 10.0Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which many backends normalize identically to dashed forms. An attacker able to reach a protected route can inject an underscore-variant header that survives Traefik's stripping and reaches the backend alongside, or on the unauthenticated ForwardAuth authResponseHeaders path instead of, the value Traefik intended to set, spoofing identity or authorization context. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.

CVSS v3
10.0
EG Score
10.0CRITICALmedium confidence
EG Risk
60
EG Risk 60/100

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)
Severity100% × 45%
Impact severity (EG Severity): CVSS 10.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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
0.2%
EPSS %ILE
15th
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 (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.

EG Severity
10.0 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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, 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; 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.

The score's inputs: 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

July 6, 2026

Last Modified

July 8, 2026

Advisory Details (3)

Auto-updated Oct 30, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_pr, github.
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Incomplete fix for CVE-2026-33433 + CVE-2026-39858 cross-cohort: headerField underscore-variant identity spoofing in BasicAuth / DigestAuth / ForwardAuth · Advisory · traefik/traefik · GitHub

Affected: v2.11.42 / v3.6.12 / v3.7.0-ea.3) added

https://github.com/traefik/traefik/security/advisories/GHSA-x677-9fxg-v5c5
GitHub pull request

Add an option to remove request headers with underscores

Fix merged in traefik/traefik PR #13262 on 2026-06-19 — awaiting tagged release

https://github.com/traefik/traefik/pull/13262
GitHub commit

commit 108a5264473a (traefik/traefik)

Fix landed in traefik/traefik commit 108a5264473a — awaiting tagged release

https://github.com/traefik/traefik/commit/108a5264473a2cbc8f12d6d691a3c6553cdf2c1b

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatdevspaces/traefik-rhel9:17877567992026-09-01redhat
gogithub.com/traefik/traefik/v2 @ 2.11.51 (fixes <= 2.11.50)—ghsa
gogithub.com/traefik/traefik/v3 @ 3.6.22 (fixes <= 3.6.21)—ghsa
gogithub.com/traefik/traefik/v3 @ 3.7.6 (fixes >= 3.7.0, <= 3.7.5)—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 2.11.51: fixed in 2.11.51
—
github.com/traefik/traefik/v3—
  • every version up to 3.6.22: fixed in 3.6.22
  • 3.7.0 up to 3.7.6: fixed in 3.7.6
—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 24× in last 7d / 81× 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 233 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 133 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  2. 2026-11-02 09:25 UTCEG score recompute
  3. 2026-11-02 09:25 UTCVendor advisory
  4. 2026-11-02 09:25 UTCGHSA enrichmentGHSA-x677-9fxg-v5c5 · GitHub severity HIGH
  5. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  6. 2026-11-01 09:30 UTCVendor advisory
  7. 2026-11-01 09:30 UTCGHSA enrichmentGHSA-x677-9fxg-v5c5 · GitHub severity HIGH
  8. 2026-11-01 07:44 UTCGHSA enrichmentGHSA-x677-9fxg-v5c5 · GitHub severity HIGH
  9. 2026-11-01 07:44 UTCEG score recompute
  10. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  11. 2026-10-31 09:37 UTCEG score recompute
  12. 2026-10-31 09:37 UTCVendor advisory
  13. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  14. 2026-10-30 09:42 UTCEG score recompute
  15. 2026-10-30 09:42 UTCVendor advisory
  16. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  17. 2026-10-29 09:48 UTCEG score recompute
  18. 2026-10-29 09:48 UTCVendor advisory
  19. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  20. 2026-10-28 09:54 UTCEG score recompute
  21. 2026-10-28 09:54 UTCVendor advisory
  22. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-27 09:08 UTCEG score recompute
  24. 2026-10-27 09:08 UTCVendor advisory
  25. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
Show 75 more
  1. 2026-10-26 08:18 UTCEG score recompute
  2. 2026-10-26 08:18 UTCVendor advisory
  3. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-25 14:19 UTCEG score recompute
  5. 2026-10-25 08:24 UTCEG score recompute
  6. 2026-10-25 08:24 UTCVendor advisory
  7. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  8. 2026-10-24 08:30 UTCEG score recompute
  9. 2026-10-24 08:30 UTCVendor advisory
  10. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  11. 2026-10-23 08:36 UTCEG score recompute
  12. 2026-10-23 08:36 UTCVendor advisory
  13. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  14. 2026-10-22 08:40 UTCEG score recompute
  15. 2026-10-22 08:40 UTCVendor advisory
  16. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-21 08:45 UTCEG score recompute
  18. 2026-10-21 08:45 UTCVendor advisory
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  20. 2026-10-20 08:51 UTCEG score recompute
  21. 2026-10-20 08:51 UTCVendor advisory
  22. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-19 08:55 UTCEG score recompute
  24. 2026-10-19 08:55 UTCVendor advisory
  25. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  26. 2026-10-18 09:00 UTCVendor advisory
  27. 2026-10-18 03:30 UTCEG score recompute
  28. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  29. 2026-10-17 07:19 UTCEG score recompute
  30. 2026-10-17 07:19 UTCVendor advisory
  31. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  32. 2026-10-16 07:23 UTCEG score recompute
  33. 2026-10-16 07:23 UTCVendor advisory
  34. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  35. 2026-10-15 06:18 UTCEG score recompute
  36. 2026-10-15 06:18 UTCVendor advisory
  37. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  38. 2026-10-14 01:57 UTCEG score recompute
  39. 2026-10-14 01:57 UTCVendor advisory
  40. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  41. 2026-10-12 22:14 UTCEG score recompute
  42. 2026-10-12 22:14 UTCVendor advisory
  43. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  44. 2026-10-12 15:56 UTCEG score recompute
  45. 2026-10-12 06:56 UTCVendor advisory
  46. 2026-10-11 19:39 UTCEG score recompute
  47. 2026-10-11 16:54 UTCEG score recompute
  48. 2026-10-11 14:17 UTCEG score recompute
  49. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  50. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  51. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  52. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  53. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  54. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  55. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  56. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  57. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  58. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  59. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  60. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  61. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  62. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  63. 2026-09-28 13:41 UTCEG score recompute
  64. 2026-09-28 13:41 UTCVendor advisory
  65. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  66. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  67. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  68. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  69. 2026-09-23 11:00 UTCVendor advisory
  70. 2026-09-23 06:22 UTCEG score recompute
  71. 2026-09-23 06:22 UTCVendor advisory
  72. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  73. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  74. 2026-09-18 10:11 UTCVendor advisory
  75. 2026-09-18 05:59 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54763?
CVE-2026-54763 is a critical-severity vulnerability; its CVE record was published on July 6, 2026. Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which…
When was the CVE record for CVE-2026-54763 published?
The CVE record for CVE-2026-54763 was published on July 6, 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 8, 2026; the record at its source may have been updated since.
Is CVE-2026-54763 actively exploited?
CVE-2026-54763 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54763?
CVE-2026-54763 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2026-54763?
A fix for CVE-2026-54763 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-54763 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54763

Explore →

Is Your Infrastructure Affected by CVE-2026-54763?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.