Vulnerability-Lookup

CVE-2026-90882 (GCVE-0-2026-90882)

Vulnerability from cvelistv5 – Published: 2026-09-22 09:27 – Updated: 2026-09-22 13:06

Title

Reflected arbitrary origins with credentials, allowing cross-origin reads of authenticated user data

Summary

The open-vsx.org deployment returned Access-Control-Allow-Origin reflecting the requesting origin together with Access-Control-Allow-Credentials: true on the authenticated /user/ endpoints. A page on any origin could therefore issue credentialed requests to the service in a logged-in user's browser and read the responses. This exposed /user (login name, avatar, homepage, tokens URL), /user/tokens, /user/namespaces, /user/extensions, /user/search/{name} and /user/namespace/{name}/members, and — because /user/csrf was readable the same way — allowed the CSRF protection on write endpoints to be defeated. Chaining the two, an attacker page could call /user/token/create and exfiltrate a personal access token carrying publish and delete rights over the victim's namespaces. The headers were emitted by the CDN/edge layer, not by the application: the Open VSX software sets allowCredentials(true) in exactly one place, against a single exact origin derived from ovsx.webui.url, and defines no CORS mapping on /user/ beyond it. No configuration of the software produces origin reflection with credentials.

Severity

8.7 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-22 13:06 UTC

CWE

CWE-942

Assigner

eclipse CNA under the mitre root

CNA scorecard C 64/100 over 189 records in the last 180 days details

References

1 reference

URL	Tags
https://gitlab.eclipse.org/security/cve-assignmen…

Impacted products

1 product

Vendor	Product	Version	CPE status
Eclipse Foundation	open-vsx.org	Affected: 29/04/2026 , ≤ 07/09/2026 (custom)	guessed

Credits

https://github.com/Char0n1507

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-90882

Vulnerability from fkie_nvd - Published: 2026-09-22 10:17 - Updated: 2026-09-22 19:09

Severity

8.7 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Summary

References

	URL	Tags
	emo@eclipse.org	https://gitlab.eclipse.org/security/cve-assignment/-/work_items/289

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-22T13:06:04.901059Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-22T10:17:10.000",
  "references": [
    {
      "source": "emo@eclipse.org",
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/289"
    }
  ],
  "sourceIdentifier": "emo@eclipse.org",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-942"
        }
      ],
      "source": "emo@eclipse.org",
      "type": "Secondary"
    }
  ]
}

GHSA-PX7G-FW3G-W264

Vulnerability from github – Published: 2026-09-22 12:30 – Updated: 2026-09-22 12:30

Details

This exposed /user (login name, avatar, homepage, tokens URL), /user/tokens, /user/namespaces, /user/extensions, /user/search/{name} and /user/namespace/{name}/members, and — because /user/csrf was readable the same way — allowed the CSRF protection on write endpoints to be defeated. Chaining the two, an attacker page could call /user/token/create and exfiltrate a personal access token carrying publish and delete rights over the victim's namespaces.

The headers were emitted by the CDN/edge layer, not by the application: the Open VSX software sets allowCredentials(true) in exactly one place, against a single exact origin derived from ovsx.webui.url, and defines no CORS mapping on /user/ beyond it. No configuration of the software produces origin reflection with credentials.

Severity

8.7 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-90882"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-942"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-22T10:17:10Z",
    "severity": "HIGH"
  },
  "details": "The open-vsx.org deployment returned Access-Control-Allow-Origin reflecting the requesting origin together with Access-Control-Allow-Credentials: true on the authenticated /user/ endpoints. A page on any origin could therefore issue credentialed requests to the service in a logged-in user\u0027s browser and read the responses.\n\n\n\nThis exposed /user (login name, avatar, homepage, tokens URL), /user/tokens, /user/namespaces, /user/extensions, /user/search/{name} and /user/namespace/{name}/members, and \u2014 because /user/csrf was readable the same way \u2014 allowed the CSRF protection on write endpoints to be defeated. Chaining the two, an attacker page could call /user/token/create and exfiltrate a personal access token carrying publish and delete rights over the victim\u0027s namespaces.\n\n\n\nThe headers were emitted by the CDN/edge layer, not by the application: the Open VSX software sets allowCredentials(true) in exactly one place, against a single exact origin derived from ovsx.webui.url, and defines no CORS mapping on /user/ beyond it. No configuration of the software produces origin reflection with credentials.",
  "id": "GHSA-px7g-fw3g-w264",
  "modified": "2026-09-22T12:30:25Z",
  "published": "2026-09-22T12:30:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90882"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/289"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/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"
    }
  ]
}

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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.

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CVE-2026-90882 (GCVE-0-2026-90882)

FKIE_CVE-2026-90882

GHSA-PX7G-FW3G-W264

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