CVE-2026-90882: Reflected arbitrary origins with credentials, allowing cross-origin reads of authenticated user data
Eclipse Foundation · open-vsx.org
Affected: Eclipse Foundation open-vsx.org · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 38% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Eclipse Foundation · open-vsx.orgfrom 29/04/2026 up to and including 07/09/2026
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Eclipse Foundation
- Published
- September 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-90882 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.