{"id":"CVE-2021-34435","aliases":["EUVD-2021-2115","GHSA-v9w2-v7j9-rjpr"],"status":"published","title":"Remote code execution in Eclipse Theia","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file..","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.00595,"percentile":0.48916,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-346","CWE-668","CWE-942"],"published":"2021-09-01T17:20:09Z","modified":"2026-10-24T10:30:27Z","fixes":[{"ecosystem":"npm","package":"@theia/mini-browser","fixed_in":["1.9.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@theia/mini-browser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.3.9"},{"fixed":"1.9.0"}]}]},{"source":"osv","ecosystem":"npm","package":"@theia/mini-browser","ranges":[{"type":"SEMVER","events":[{"introduced":"0.3.9"},{"fixed":"1.9.0"}]}]}],"products":[{"vendor":"eclipse","product":"theia"},{"vendor":"the eclipse foundation","product":"eclipse theia"}],"references":[{"url":"https://bugs.eclipse.org/bugs/show_bug.cgi?id=568018","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Patch","Vendor Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34435","tags":["advisory"]},{"url":"https://github.com/eclipse-theia/theia/pull/8759","tags":["web"]},{"url":"https://github.com/eclipse-theia/theia/commit/0761dcf5fe3c14c27432683d42d2c526ad0cfbd5","tags":["web"]},{"url":"https://github.com/advisories/GHSA-v9w2-v7j9-rjpr"},{"url":"https://github.com/eclipse-theia/theia","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-34435","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file..","status":"published","published":"2021-09-01T17:20:09Z","modified":"2024-08-04T00:12:50.149Z","cwes":["CWE-942"],"updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-2115","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file..","status":"published","published":"2021-09-01T17:20:09Z","modified":"2024-08-04T00:12:50Z","updated_at":"2026-11-03T03:24:32.445199Z"}],"ghsa":[{"id":"GHSA-v9w2-v7j9-rjpr","title":"Remote code execution in Eclipse Theia","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file.","status":"published","published":"2021-09-02T22:02:36Z","modified":"2023-01-29T05:07:50Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-346","CWE-668","CWE-942"],"updated_at":"2026-11-02T14:36:26.667347Z"}],"nvd":[{"id":"CVE-2021-34435","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file..","status":"published","published":"2021-09-01T18:15:09.107Z","modified":"2026-06-17T03:55:51.733Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-942","CWE-346"],"updated_at":"2026-11-02T14:06:58.05696Z"}],"osv":[{"id":"CVE-2021-34435","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file..","status":"published","published":"2021-09-01T18:15:09.107Z","modified":"2026-10-24T10:30:27.405444827Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:20.13324Z"},{"id":"GHSA-v9w2-v7j9-rjpr","title":"Remote code execution in Eclipse Theia","description":"In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file.","status":"published","published":"2021-09-02T22:02:36Z","modified":"2023-11-08T04:06:07.936867Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-346","CWE-668","CWE-942"],"updated_at":"2026-11-02T15:46:56.981655Z"}]}}