CVE-2026-40575

CRITICALPre-NVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (41st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-24557 (ENISA EUVD) · GHSA-7x63-xv5r-3p2x (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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions 7.5.0 through 7.15.1 may trust a client-supplied X-Forwarded-Uri header when --reverse-proxy is enabled and --skip-auth-regex or --skip-auth-route is configured. An attacker can spoof this header so OAuth2 Proxy evaluates authentication and skip-auth rules against a different path than the one actually sent to the upstream application. This can result in an unauthenticated remote attacker bypassing authentication and accessing protected routes without a valid session. Impacted users are deployments that run oauth2-proxy with --reverse-proxy enabled and configure at least one --skip-auth-regex or --skip-auth-route rule. This issue is patched in v7.15.2. Some workarounds are available for those who cannot upgrade immediately. Strip any client-provided X-Forwarded-Uri header at the reverse proxy or load balancer level; explicitly overwrite X-Forwarded-Uri with the actual request URI before forwarding requests to OAuth2 Proxy; restrict direct client access to OAuth2 Proxy so it can only be reached through a trusted reverse proxy; and/or remove or narrow --skip-auth-regex / --skip-auth-route rules where possible. For nginx-based deployments, ensure X-Forwarded-Uri is set by nginx and not passed through from the client.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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.
Exploitation0.5% × 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 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
41st
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.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). 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: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: 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 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.

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

April 22, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Sep 16, 2026
Patch available. Sources: github, redhat.
Red Hat
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40575.json
Red Hat

2460449 – (CVE-2026-40575) CVE-2026-40575 oauth2-proxy: github.com/oauth2-proxy/oauth2-proxy: OAuth2 Proxy: Authentication bypass due to spoofed X-Forwarded-Uri header

https://bugzilla.redhat.com/show_bug.cgi?id=2460449
Red HatMentions a patch (unverified)

CVE-2026-40575 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-40575
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

Vendor Advisories for CVE-2026-40575(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-7.15.4-0.1.hum12026-08-22redhat

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 22× in last 7d / 72× 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 99 of 234 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 135 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-30 06:44 UTCEG score recompute
  2. 2026-10-30 06:44 UTCVendor advisory
  3. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  4. 2026-10-29 07:38 UTCEG score recompute
  5. 2026-10-29 07:38 UTCVendor advisory
  6. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  7. 2026-10-28 08:33 UTCEG score recompute
  8. 2026-10-28 08:33 UTCVendor advisory
  9. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  10. 2026-10-27 09:05 UTCEG score recompute
  11. 2026-10-27 09:05 UTCVendor advisory
  12. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  13. 2026-10-26 08:57 UTCEG score recompute
  14. 2026-10-26 08:57 UTCVendor advisory
  15. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  16. 2026-10-25 14:30 UTCEG score recompute
  17. 2026-10-25 09:52 UTCEG score recompute
  18. 2026-10-25 09:52 UTCVendor advisory
  19. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  20. 2026-10-24 10:46 UTCEG score recompute
  21. 2026-10-24 10:46 UTCVendor advisory
  22. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  23. 2026-10-23 11:40 UTCEG score recompute
  24. 2026-10-23 11:40 UTCVendor advisory
  25. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
Show 74 more
  1. 2026-10-22 12:32 UTCEG score recompute
  2. 2026-10-22 12:32 UTCVendor advisory
  3. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  4. 2026-10-21 13:27 UTCEG score recompute
  5. 2026-10-21 13:27 UTCVendor advisory
  6. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  7. 2026-10-20 14:19 UTCEG score recompute
  8. 2026-10-20 14:19 UTCVendor advisory
  9. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  10. 2026-10-19 13:22 UTCEG score recompute
  11. 2026-10-19 13:22 UTCVendor advisory
  12. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  13. 2026-10-18 12:46 UTCVendor advisory
  14. 2026-10-18 03:42 UTCEG score recompute
  15. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  16. 2026-10-17 13:40 UTCEG score recompute
  17. 2026-10-17 13:40 UTCVendor advisory
  18. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  19. 2026-10-16 14:33 UTCEG score recompute
  20. 2026-10-16 14:33 UTCVendor advisory
  21. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  22. 2026-10-15 15:11 UTCEG score recompute
  23. 2026-10-15 15:11 UTCVendor advisory
  24. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  25. 2026-10-14 09:33 UTCEG score recompute
  26. 2026-10-14 09:33 UTCVendor advisory
  27. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  28. 2026-10-13 07:12 UTCEG score recompute
  29. 2026-10-13 07:12 UTCVendor advisory
  30. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  31. 2026-10-12 16:09 UTCEG score recompute
  32. 2026-10-12 08:05 UTCVendor advisory
  33. 2026-10-11 19:51 UTCEG score recompute
  34. 2026-10-11 17:05 UTCEG score recompute
  35. 2026-10-11 14:31 UTCEG score recompute
  36. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  37. 2026-10-11 05:55 UTCOSV refresh
  38. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  39. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  40. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  41. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  42. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  43. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  44. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  45. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  46. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  47. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  48. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  49. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  50. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  51. 2026-09-21 17:49 UTCOSV refresh
  52. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  53. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  54. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  55. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  56. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  57. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  58. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  59. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  60. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  61. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  62. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  63. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  64. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  65. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  66. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  67. 2026-09-02 14:31 UTCOSV refresh
  68. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  69. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  70. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  71. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  72. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  73. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  74. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 39th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-40575?
CVE-2026-40575 is a critical-severity vulnerability; its CVE record was published on April 22, 2026. OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions 7.5.0 through 7.15.1 may trust a client-supplied X-Forwarded-Uri header when --reverse-proxy is enabled and --skip-auth-regex or --skip-auth-route is configured. An attacker can spoof this header so OAuth2…
When was the CVE record for CVE-2026-40575 published?
The CVE record for CVE-2026-40575 was published on April 22, 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 15, 2026; the record at its source may have been updated since.
Is CVE-2026-40575 actively exploited?
CVE-2026-40575 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40575?
CVE-2026-40575 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-2026-40575?
A fix for CVE-2026-40575 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40575 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-2026-40575

Explore →

Is Your Infrastructure Affected by CVE-2026-40575?

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

Book a Demo →Browse All CVEs