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.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Eclipse Foundation | open-vsx.org | unaffected |
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No vendor fix or workaround currently provided.
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Tracking
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Tue, 22 Sep 2026 09:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Reflected arbitrary origins with credentials, allowing cross-origin reads of authenticated user data | |
| Weaknesses | CWE-942 | |
| References |
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| Metrics |
cvssV4_0
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: eclipse
Published:
Updated: 2026-09-22T09:27:34.713Z
Reserved: 2026-09-14T07:44:22.377Z
Link: CVE-2026-90882
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-22T10:17:10.000
Modified: 2026-09-22T10:17:10.000
Link: CVE-2026-90882
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-09-22T10:30:17Z