{"id":"CVE-2021-26271","aliases":["DEBIAN-CVE-2021-26271","EUVD-2022-4431","GHSA-jv4c-7jqq-m34x","UBUNTU-CVE-2021-26271"],"status":"published","title":"CKEditor 4 ReDoS Vulnerability","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01994,"percentile":0.80861,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1333","CWE-829"],"published":"2021-01-26T20:39:46Z","modified":"2026-10-24T10:50:07Z","fixes":[{"ecosystem":"npm","package":"ckeditor4-dev","fixed_in":["4.16"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"ckeditor","fixed_in":["4.16.0+dfsg-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"ckeditor4-dev","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.16"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"ckeditor","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.16.0+dfsg-1"}]}]},{"source":"osv","ecosystem":"npm","package":"ckeditor4-dev","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.16"}]}]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"ckeditor","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.4+dfsg1-3","4.5.6+dfsg-1","4.5.7+dfsg-1","4.5.7+dfsg-2","4.5.7+dfsg-2ubuntu0.16.04.1~esm1","4.5.7+dfsg-2ubuntu0.16.04.1~esm2","4.5.7+dfsg-2ubuntu0.16.04.1~esm3"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"ckeditor","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.5.7+dfsg-2","4.5.7+dfsg-2ubuntu0.18.04.1","4.5.7+dfsg-2ubuntu0.18.04.1+esm1","4.5.7+dfsg-2ubuntu0.18.04.1+esm2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"ckeditor","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.11.1+dfsg-1","4.12.1+dfsg-1","4.12.1+dfsg-1ubuntu0.1","4.12.1+dfsg-1ubuntu0.1+esm1","4.12.1+dfsg-1ubuntu0.1+esm2"]}],"products":[{"vendor":"ckeditor","product":"ckeditor"},{"vendor":"oracle","product":"agile_product_lifecycle_management"},{"vendor":"oracle","product":"application_express"},{"vendor":"oracle","product":"financial_services_analytical_applications_infrastructure"},{"vendor":"oracle","product":"jd_edwards_enterpriseone_tools"},{"vendor":"oracle","product":"siebel_ui_framework"},{"vendor":"oracle","product":"webcenter_sites"}],"references":[{"url":"https://github.com/ckeditor/ckeditor4/blob/major/CHANGES.md#ckeditor-416","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory","web","report"]},{"url":"https://www.oracle.com//security-alerts/cpujul2021.html","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://ckeditor.com/blog/CKEditor-4.16-with-improved-image-pasting-High-Contrast-support-and-a-new-color-API/#security-comes-first","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory"]},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26271","tags":["advisory"]},{"url":"https://web.archive.org/web/20210128132707/https://ckeditor.com/blog/CKEditor-4.16-with-improved-image-pasting-High-Contrast-support-and-a-new-color-API/#security-comes-first","tags":["web"]},{"url":"https://github.com/advisories/GHSA-jv4c-7jqq-m34x"},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-26271","tags":["advisory"]},{"url":"https://github.com/ckeditor/ckeditor4","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2021-26271","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-26271","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-26271","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2021-01-26T20:39:46Z","modified":"2024-08-03T20:19:20.393Z","updated_at":"2026-11-02T14:32:57.033395Z"}],"euvd":[{"id":"EUVD-2022-4431","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2021-01-26T20:39:46Z","modified":"2024-08-03T20:19:20Z","updated_at":"2026-11-03T03:24:51.962182Z"}],"ghsa":[{"id":"GHSA-jv4c-7jqq-m34x","title":"CKEditor 4 ReDoS Vulnerability","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2022-05-24T17:40:21Z","modified":"2024-04-22T23:14:44Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T14:37:44.335614Z"}],"nvd":[{"id":"CVE-2021-26271","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2021-01-26T21:15:12.86Z","modified":"2026-08-25T16:28:27.31Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-829"],"updated_at":"2026-11-02T14:06:49.660551Z"}],"osv":[{"id":"CVE-2021-26271","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2021-01-26T21:15:12.86Z","modified":"2026-10-24T10:50:07.4055474Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:18.778776Z"},{"id":"DEBIAN-CVE-2021-26271","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2021-01-26T21:15:12.86Z","modified":"2026-10-23T18:03:02.979957182Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:34.637046Z"},{"id":"GHSA-jv4c-7jqq-m34x","title":"CKEditor 4 ReDoS Vulnerability","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2022-05-24T17:40:21Z","modified":"2026-09-10T03:49:39.067777385Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-1333"],"updated_at":"2026-11-02T15:46:51.10002Z"},{"id":"UBUNTU-CVE-2021-26271","description":"It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).","status":"published","published":"2021-01-26T21:15:00Z","modified":"2026-02-04T06:29:56.200608Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:54:26.779273Z"}]}}