CVE-2026-76835

CRITICALPre-NVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-24. A secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-65061 (ENISA EUVD) · GHSA-vvqv-7vrf-88vh (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.1Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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
9.1CRITICALmedium confidence
EG Risk
72
EG Risk 72/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
39th
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 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, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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)3 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 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

August 24, 2026

Last Modified

October 13, 2026

Advisory Details (5)

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

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 advisoryMentions a patch (unverified)

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
Web page

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
Web page

[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
Web page

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(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 / EcosystemFix (by version range) / PatchReleasedSource
redhatoauth2-proxy-main-7.15.5-0.1.hum12026-10-01redhat

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

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFix by version rangeDependents
github.com/oauth2-proxy/oauth2-proxy—
  • every version on: no fix on record
—
github.com/oauth2-proxy/oauth2-proxy/v7—
  • 7.5.0 up to 7.15.2: fixed in 7.15.2
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 169× 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 486 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 386 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 05:52 UTCEG score recompute
  2. 2026-11-02 05:52 UTCVendor advisory
  3. 2026-11-02 05:52 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  4. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-11-01 05:06 UTCEG score recompute
  6. 2026-11-01 05:06 UTCVendor advisory
  7. 2026-11-01 05:06 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  8. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-10-31 04:21 UTCEG score recompute
  10. 2026-10-31 04:21 UTCVendor advisory
  11. 2026-10-31 04:21 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  12. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-10-30 03:34 UTCEG score recompute
  14. 2026-10-30 03:34 UTCVendor advisory
  15. 2026-10-30 03:34 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  16. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  17. 2026-10-29 02:49 UTCEG score recompute
  18. 2026-10-29 02:49 UTCVendor advisory
  19. 2026-10-29 02:49 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  20. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  21. 2026-10-28 02:02 UTCEG score recompute
  22. 2026-10-28 02:02 UTCVendor advisory
  23. 2026-10-28 02:02 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  25. 2026-10-27 01:14 UTCEG score recompute
Show 75 more
  1. 2026-10-27 01:14 UTCVendor advisory
  2. 2026-10-27 01:13 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-10-25 20:38 UTCEG score recompute
  5. 2026-10-25 20:38 UTCVendor advisory
  6. 2026-10-25 20:38 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  7. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  8. 2026-10-25 14:01 UTCEG score recompute
  9. 2026-10-24 19:53 UTCEG score recompute
  10. 2026-10-24 19:53 UTCVendor advisory
  11. 2026-10-24 19:53 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  12. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  13. 2026-10-23 19:08 UTCEG score recompute
  14. 2026-10-23 19:08 UTCVendor advisory
  15. 2026-10-23 19:08 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  16. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  17. 2026-10-22 18:20 UTCEG score recompute
  18. 2026-10-22 18:20 UTCVendor advisory
  19. 2026-10-22 18:20 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  20. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  21. 2026-10-21 17:35 UTCEG score recompute
  22. 2026-10-21 17:35 UTCVendor advisory
  23. 2026-10-21 17:35 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  25. 2026-10-20 16:49 UTCEG score recompute
  26. 2026-10-20 16:49 UTCVendor advisory
  27. 2026-10-20 16:49 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  28. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  29. 2026-10-19 22:04 UTCEG score recompute
  30. 2026-10-19 22:04 UTCVendor advisory
  31. 2026-10-19 22:04 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  32. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  33. 2026-10-18 20:53 UTCEG score recompute
  34. 2026-10-18 20:53 UTCVendor advisory
  35. 2026-10-18 20:53 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  36. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  37. 2026-10-18 03:12 UTCEG score recompute
  38. 2026-10-17 20:08 UTCEG score recompute
  39. 2026-10-17 20:08 UTCVendor advisory
  40. 2026-10-17 20:08 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  41. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  42. 2026-10-16 19:19 UTCEG score recompute
  43. 2026-10-16 19:19 UTCVendor advisory
  44. 2026-10-16 19:19 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  45. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  46. 2026-10-15 16:54 UTCEG score recompute
  47. 2026-10-15 16:54 UTCVendor advisory
  48. 2026-10-15 16:54 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  49. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  50. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  51. 2026-10-14 10:50 UTCEG score recompute
  52. 2026-10-14 10:50 UTCVendor advisory
  53. 2026-10-14 10:50 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  54. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  55. 2026-10-13 09:27 UTCVendor advisory
  56. 2026-10-13 09:26 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  57. 2026-10-12 21:50 UTCEG score recompute
  58. 2026-10-12 21:50 UTCVendor advisory
  59. 2026-10-12 21:50 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  60. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  61. 2026-10-12 15:38 UTCEG score recompute
  62. 2026-10-12 05:31 UTCVendor advisory
  63. 2026-10-12 05:30 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  64. 2026-10-11 19:23 UTCEG score recompute
  65. 2026-10-11 16:39 UTCEG score recompute
  66. 2026-10-11 13:58 UTCEG score recompute
  67. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  68. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  69. 2026-10-10 16:23 UTCVendor advisory
  70. 2026-10-10 16:23 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  71. 2026-10-10 12:33 UTCEG score recompute
  72. 2026-10-10 12:33 UTCVendor advisory
  73. 2026-10-10 12:32 UTCGHSA enrichmentGHSA-vvqv-7vrf-88vh · GitHub severity CRITICAL · GitHub CVSS 9.1
  74. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  75. 2026-10-09 08:24 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-76835?
CVE-2026-76835 is a critical-severity vulnerability; its CVE record was 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 made public?
CVE-2026-76835 was made public on August 17, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 24, 2026. EchelonGraph's copy of the record carries a last-modified date of October 13, 2026; the record at its source may have been updated since.
Is CVE-2026-76835 actively exploited?
CVE-2026-76835 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-76835?
CVE-2026-76835 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-76835?
A fix for CVE-2026-76835 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-76835 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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