CVE-2026-76835

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-24. the CNA's CVSS baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this weekElevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: Elevated riskExposed: 0

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

OAuth2 Proxy honours a client-supplied X-Forwarded-Uri header when deciding whether a request may skip authentication, because the guard added for CVE-2026-40575 is inert in the default reverse-proxy configuration. GetRequestURI in pkg/requests/util/util.go prefers that header over the real request URI whenever CanTrustForwardedHeaders returns true, and isAllowedPath in oauthproxy.go matches the skip_auth_routes and skip_auth_regex allow list against the resulting path. CanTrustForwardedHeaders in pkg/apis/middleware/scope.go grants that trust when the caller's address is in the trusted proxy set, and buildTrustedProxyNetSet falls back to defaultTrustedProxyIPs, which is 0.0.0.0/0 and ::/0, whenever reverse proxy mode is enabled without trusted_proxy_ip configured. Every client is therefore treated as a trusted proxy. An unauthenticated attacker can request a protected upstream path while setting X-Forwarded-Uri to a value matching an allow-listed route, so the skip-auth decision is made against the spoofed value while the upstream receives the protected path unchanged.

CVSS v3
9.1
EG Score
9.1(high)
EG Risk
72(Attend)
EG Risk 72/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

August 24, 2026

Last Modified

August 29, 2026

Advisory Details (5)

Auto-updated Sep 15, 2026
Patch available. Sources: github.
generic

OAuth2 Proxy 7.15.2 through 7.15.4 Authentication Bypass via X-Forwarded-Uri Under the Default Trusted Proxy Set | Advisories | VulnCheck

https://www.vulncheck.com/advisories/oauth2-proxy-through-authentication-bypass-via-x-forwarded-uri-under-the-default-trusted-proxy-set
github Patch Available

Authentication Bypass via X-Forwarded-Uri Header Spoofing · Advisory · oauth2-proxy/oauth2-proxy · GitHub

https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-7x63-xv5r-3p2x
generic

oauth2-proxy/pkg/apis/middleware/scope.go at v7.15.4 · oauth2-proxy/oauth2-proxy · GitHub

https://github.com/oauth2-proxy/oauth2-proxy/blob/v7.15.4/pkg/apis/middleware/scope.go
generic

[Bug]: Auth bypass: spoofed X-Forwarded-Uri skips auth for protected upstream paths under default reverse-proxy config · Issue #3506 · oauth2-proxy/oauth2-proxy · GitHub

https://github.com/oauth2-proxy/oauth2-proxy/issues/3506
generic

GitHub - oauth2-proxy/oauth2-proxy: A reverse proxy that provides authentication with Google, Azure, OpenID Connect and many more identity providers. · GitHub

https://github.com/oauth2-proxy/oauth2-proxy

Vendor Advisories for CVE-2026-76835(1)

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

Affected Packages

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/oauth2-proxy/oauth2-proxy———
github.com/oauth2-proxy/oauth2-proxy/v7—7.15.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 55× in last 7d / 212× 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.

Showing the most recent 100 of 212 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-76835?
CVE-2026-76835 is a critical vulnerability published on August 24, 2026. OAuth2 Proxy honours a client-supplied X-Forwarded-Uri header when deciding whether a request may skip authentication, because the guard added for CVE-2026-40575 is inert in the default reverse-proxy configuration. GetRequestURI in pkg/requests/util/util.go prefers that header over the real request…
When was CVE-2026-76835 disclosed?
CVE-2026-76835 was first published in the National Vulnerability Database on August 24, 2026, with the most recent update on August 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-76835 actively exploited?
CVE-2026-76835 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 71.7% of all scored CVEs.
What is the CVSS score of CVE-2026-76835?
CVE-2026-76835 has a CVSS v4.0 base score of 9.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-76835?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-76835, 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.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-76835

Explore →

Is Your Infrastructure Affected by CVE-2026-76835?

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

Start Free Scan →Browse All CVEs