Vulnerability-Lookup

GHSA-M5W8-4879-F4PC

Vulnerability from github – Published: 2026-08-25 12:31 – Updated: 2026-08-25 12:31

Details

Ech0 through 4.5.6 contains an OAuth redirect URI validation vulnerability in parseAndValidateClientRedirect (internal/service/auth/auth.go) that compares only the scheme and host of the client-supplied redirect_uri against the admin-configured allowlist, ignoring path, query, and fragment components. The redirect_uri is embedded into the signed state JWT at login time without validation. An attacker can craft a redirect_uri whose host matches an allowed origin but whose path is attacker-influenced; after the OAuth exchange the victim is redirected to that path with a one-time exchange code in the query string. If the code leaks (e.g., via Referer, analytics, or an open redirect on that host), the attacker can trade it at the public POST /api/auth/exchange endpoint for the victim's access and refresh tokens. Fixed in 4.7.3.

Severity

8.0 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

8.8 (High)


                  
                    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-79662"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-25T12:16:31Z",
    "severity": "HIGH"
  },
  "details": "Ech0 through 4.5.6 contains an OAuth redirect URI validation vulnerability in parseAndValidateClientRedirect (internal/service/auth/auth.go) that compares only the scheme and host of the client-supplied redirect_uri against the admin-configured allowlist, ignoring path, query, and fragment components. The redirect_uri is embedded into the signed state JWT at login time without validation. An attacker can craft a redirect_uri whose host matches an allowed origin but whose path is attacker-influenced; after the OAuth exchange the victim is redirected to that path with a one-time exchange code in the query string. If the code leaks (e.g., via Referer, analytics, or an open redirect on that host), the attacker can trade it at the public POST /api/auth/exchange endpoint for the victim\u0027s access and refresh tokens. Fixed in 4.7.3.",
  "id": "GHSA-m5w8-4879-f4pc",
  "modified": "2026-08-25T12:31:26Z",
  "published": "2026-08-25T12:31:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lin-snow/Ech0/security/advisories/GHSA-p64j-f4x9-wq66"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-79662"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/ech0-before-oauth-redirect-uri-validation-bypass"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-79662 (GCVE-0-2026-79662)

Vulnerability from cvelistv5 – Published: 2026-08-25 11:33 – Updated: 2026-08-25 14:51

Title

Ech0 before 4.7.3 OAuth Redirect URI Validation Bypass

Summary

Severity

8.8 (High)


                        
                          CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

8 (High)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-25 14:30 UTC

CWE

CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/lin-snow/Ech0/security/advisor…	vendor-advisory
https://www.vulncheck.com/advisories/ech0-before-…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
lin-snow	Ech0	Affected: 0 , < 4.7.3 (semver) Unaffected: 4.7.3 (semver) cpe:2.3:a:ech0:ech0::::::::

Date Public

2026-05-03 00:00

Credits

adrgs aisafe-bot

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JSON

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        "metrics": [
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                "id": "CVE-2026-79662",
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                  },
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                  },
                  {
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                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-25T14:30:56.555580Z",
                "version": "2.0.3"
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        "providerMetadata": {
          "dateUpdated": "2026-08-25T14:51:03.397Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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          }
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        "title": "CISA ADP Vulnrichment"
      }
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              "status": "affected",
              "version": "0",
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        {
          "name": "VulnCheck Advisory: Ech0 before 4.7.3 OAuth Redirect URI Validation Bypass",
          "tags": [
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-M5W8-4879-F4PC

CVE-2026-79662 (GCVE-0-2026-79662)

Tags

Sightings

Nomenclature