CVE-2026-54763

CRITICALNVD 10.010.0—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 10.0 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 83% 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 — 4 sources updated this week
10.0
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 10.0Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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
10.0(medium)
EPSS
16.9%
KEV
Not listed

Published

July 6, 2026

Last Modified

July 8, 2026

Advisory Details (3)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_pr.
github Patch Available🟡 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_pr

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

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 37× in last 7d / 37× 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.

  1. 2026-07-11 21:34 UTCEG score recompute
  2. 2026-07-11 17:24 UTCEG score recompute
  3. 2026-07-11 13:14 UTCEG score recompute
  4. 2026-07-11 09:03 UTCEG score recompute
  5. 2026-07-11 08:27 UTCEPSS rescore
  6. 2026-07-11 08:27 UTCEPSS rescore
  7. 2026-07-11 04:51 UTCEG score recompute
  8. 2026-07-11 00:40 UTCEG score recompute
  9. 2026-07-10 20:29 UTCEG score recompute
  10. 2026-07-10 16:19 UTCEG score recompute
  11. 2026-07-10 12:06 UTCEG score recompute
  12. 2026-07-10 07:55 UTCEG score recompute
  13. 2026-07-10 03:45 UTCEG score recompute
  14. 2026-07-09 23:33 UTCEG score recompute
  15. 2026-07-09 19:23 UTCEG score recompute
  16. 2026-07-09 19:10 UTCEPSS rescore
  17. 2026-07-09 19:10 UTCEPSS rescore
  18. 2026-07-09 15:12 UTCEG score recompute
  19. 2026-07-09 10:57 UTCEG score recompute
  20. 2026-07-09 06:47 UTCEG score recompute
  21. 2026-07-09 02:35 UTCEG score recompute
  22. 2026-07-08 22:23 UTCEG score recompute
  23. 2026-07-08 20:53 UTCNVD updateCVSS v3 → 10 · severity → CRITICAL
  24. 2026-07-08 19:44 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  25. 2026-07-08 18:12 UTCEG score recompute
Show 12 more
  1. 2026-07-08 15:16 UTCEPSS rescore
  2. 2026-07-08 15:16 UTCEPSS rescore
  3. 2026-07-08 14:03 UTCEG score recompute
  4. 2026-07-08 09:51 UTCEG score recompute
  5. 2026-07-08 05:41 UTCEG score recompute▲ 2.20
  6. 2026-07-08 04:32 UTCNVD updateCVSS v3 → 10 · severity → CRITICAL
  7. 2026-07-07 18:50 UTCEG score recompute
  8. 2026-07-07 13:46 UTCEPSS rescore
  9. 2026-07-07 13:46 UTCEPSS rescore
  10. 2026-07-07 07:55 UTCEG score recompute
  11. 2026-07-06 21:06 UTCEG score recompute
  12. 2026-07-06 21:04 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-54763?
CVE-2026-54763 is a critical vulnerability 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 CVE-2026-54763 disclosed?
CVE-2026-54763 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54763 actively exploited?
CVE-2026-54763 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54763, 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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