{"id":"CVE-2019-16216","aliases":["EUVD-2019-7028","GHSA-j2r8-2vxg-pxvh"],"status":"published","title":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is...","description":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.","severity":{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.00681,"percentile":0.52772,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2019-09-18T11:08:09Z","modified":"2026-10-20T10:52:25Z","products":[{"vendor":"zulip","product":"zulip_server"}],"references":[{"url":"https://blog.zulip.org/2019/09/11/zulip-server-2-0-5-security-release/","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory"]},{"url":"https://github.com/zulip/zulip/commit/1195841dfb9aa26b3b0dabc6f05d72e4af25be3e","tags":["x_refsource_CONFIRM","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-16216"},{"url":"https://github.com/advisories/GHSA-j2r8-2vxg-pxvh"}],"sources":{"cve":[{"id":"CVE-2019-16216","description":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.","status":"published","published":"2019-09-18T11:08:09Z","modified":"2024-08-05T01:10:41.549Z","updated_at":"2026-11-02T14:32:23.485011Z"}],"euvd":[{"id":"EUVD-2019-7028","description":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.","status":"published","published":"2019-09-18T11:08:09Z","modified":"2024-08-05T01:10:41Z","updated_at":"2026-11-03T02:40:33.71788Z"}],"ghsa":[{"id":"GHSA-j2r8-2vxg-pxvh","title":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is...","description":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.","status":"published","published":"2022-05-24T22:00:37Z","modified":"2023-01-30T05:04:11Z","updated_at":"2026-11-02T14:46:59.354373Z"}],"nvd":[{"id":"CVE-2019-16216","description":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.","status":"published","published":"2019-09-18T12:15:10.99Z","modified":"2026-06-17T02:21:54.84Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":3.5,"vector":"AV:N/AC:M/Au:S/C:N/I:P/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:05:28.126831Z"}],"osv":[{"id":"CVE-2019-16216","description":"Zulip server before 2.0.5 incompletely validated the MIME types of uploaded files. A user who is logged into the server could upload files of certain types to mount a stored cross-site scripting attack on other logged-in users. On a Zulip server using the default local uploads backend, the attack is only effective against browsers lacking support for Content-Security-Policy such as Internet Explorer 11. On a Zulip server using the S3 uploads backend, the attack is confined to the origin of the configured S3 uploads hostname and cannot reach the Zulip server itself.","status":"published","published":"2019-09-18T12:15:10.99Z","modified":"2026-10-20T10:52:25.955960798Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:11.361782Z"}]}}