{"id":"CVE-2021-32763","aliases":["EUVD-2021-19531","GHSA-qqvp-j6gm-q56f"],"status":"published","title":"Regular Expression Denial of Service in OpenProject forum messages","description":"OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `\u003cpre\u003e` tags from the message being quoted. The `(.|\\s)` part can match a space character in two ways, so an unterminated `\u003cpre\u003e` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2\u003csup\u003en\u003c/sup\u003e states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.","severity":{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00921,"percentile":0.60622,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-400"],"published":"2021-07-20T16:50:10Z","modified":"2026-10-20T10:54:42Z","products":[{"vendor":"openproject","product":"openproject"},{"vendor":"opf","product":"openproject"}],"references":[{"url":"https://github.com/opf/openproject/security/advisories/GHSA-qqvp-j6gm-q56f","tags":["x_refsource_CONFIRM","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://github.com/opf/openproject/pull/9447.patch","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix"]}],"sources":{"cve":[{"id":"CVE-2021-32763","title":"Regular Expression Denial of Service in OpenProject forum messages","description":"OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `\u003cpre\u003e` tags from the message being quoted. The `(.|\\s)` part can match a space character in two ways, so an unterminated `\u003cpre\u003e` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2\u003csup\u003en\u003c/sup\u003e states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.","status":"published","published":"2021-07-20T16:50:10Z","modified":"2024-08-03T23:33:55.735Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:33:07.014772Z"}],"euvd":[{"id":"EUVD-2021-19531","description":"OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `\u003cpre\u003e` tags from the message being quoted. The `(.|\\s)` part can match a space character in two ways, so an unterminated `\u003cpre\u003e` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2\u003csup\u003en\u003c/sup\u003e states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.","status":"published","published":"2021-07-20T16:50:10Z","modified":"2024-08-03T23:33:55Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-03T03:24:35.855495Z"}],"nvd":[{"id":"CVE-2021-32763","description":"OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `\u003cpre\u003e` tags from the message being quoted. The `(.|\\s)` part can match a space character in two ways, so an unterminated `\u003cpre\u003e` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2\u003csup\u003en\u003c/sup\u003e states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.","status":"published","published":"2021-07-20T17:15:07.813Z","modified":"2026-06-17T03:53:34.867Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:06:56.185362Z"}],"osv":[{"id":"CVE-2021-32763","description":"OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `\u003cpre\u003e` tags from the message being quoted. The `(.|\\s)` part can match a space character in two ways, so an unterminated `\u003cpre\u003e` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2\u003csup\u003en\u003c/sup\u003e states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.","status":"published","published":"2021-07-20T17:15:07.813Z","modified":"2026-10-20T10:54:42.784937288Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:19.793849Z"}]}}