{"id":"CVE-2021-43794","aliases":["BIT-discourse-2021-43794","EUVD-2021-30690","GHSA-249g-pc77-65hp"],"status":"published","title":"Anonymous user cache poisoning via development-mode header in Discourse","description":"Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0105,"percentile":0.64685,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-610"],"published":"2021-12-01T19:40:10Z","modified":"2026-10-20T10:55:04Z","fixes":[{"ecosystem":"Bitnami","package":"discourse","fixed_in":["2.7.11"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"discourse","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.7.11"}]}]}],"products":[{"vendor":"discourse","product":"discourse"}],"references":[{"url":"https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","advisory","fix"]},{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hp","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-43794","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-43794","title":"Anonymous user cache poisoning via development-mode header in Discourse","description":"Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.","status":"published","published":"2021-12-01T19:40:10Z","modified":"2024-08-04T04:03:08.879Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-610"],"updated_at":"2026-11-02T14:32:57.033395Z"}],"euvd":[{"id":"EUVD-2021-30690","description":"Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.","status":"published","published":"2021-12-01T19:40:10Z","modified":"2024-08-04T04:03:08Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-03T03:24:13.193734Z"}],"nvd":[{"id":"CVE-2021-43794","description":"Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.","status":"published","published":"2021-12-01T20:15:08.727Z","modified":"2026-06-17T04:11:27.187Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-610"],"updated_at":"2026-11-02T14:07:01.811115Z"}],"osv":[{"id":"CVE-2021-43794","description":"Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.","status":"published","published":"2021-12-01T20:15:08.727Z","modified":"2026-10-20T10:55:04.026050407Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-02T15:44:21.877444Z"},{"id":"BIT-discourse-2021-43794","title":"Anonymous user cache poisoning via development-mode header in Discourse","description":"Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.","status":"published","published":"2024-03-06T11:08:42.616Z","modified":"2026-09-08T08:46:01.140871152Z","updated_at":"2026-11-02T15:28:28.70813Z"}]}}