{"id":"CVE-2026-28405","state":"PUBLISHED","title":"MarkUs: Stored XSS in Submission HTML Preview Enables Instructor-Context Actions","description":"MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.1, the courses/<:course_id>/assignments/<:assignment_id>/submissions/html_content route reads the contents of a student-submitted file and renders them without sanitization. This issue has been patched in version 2.9.1.","publishedAt":"2026-03-05T20:06:13.433Z","updatedAt":"2026-03-06T17:04:05.190Z","severity":{"score":8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["MarkUsProject Markus"],"affected":[{"vendor":"MarkUsProject","product":"Markus","versions":[{"version":"< 2.9.1","status":"affected"}]}],"references":["https://github.com/MarkUsProject/Markus/security/advisories/GHSA-p5pc-pxrj-3893","https://github.com/MarkUsProject/Markus/commit/55d74f2ddb72d2ec2f29aa2b4cb6b2da10755036","https://github.com/MarkUsProject/Markus/releases/tag/v2.9.1"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/28xxx/CVE-2026-28405.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-28405","state":"PUBLISHED","datePublished":"2026-03-05T20:06:13.433Z","dateUpdated":"2026-03-06T17:04:05.190Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-27T15:33:57.289Z"},"containers":{"cna":{"title":"MarkUs: Stored XSS in Submission HTML Preview Enables Instructor-Context Actions","descriptions":[{"lang":"en","value":"MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.1, the courses/<:course_id>/assignments/<:assignment_id>/submissions/html_content route reads the contents of a student-submitted file and renders them without sanitization. This issue has been patched in version 2.9.1."}],"affected":[{"vendor":"MarkUsProject","product":"Markus","versions":[{"version":"< 2.9.1","status":"affected"}]}],"references":[{"url":"https://github.com/MarkUsProject/Markus/security/advisories/GHSA-p5pc-pxrj-3893","name":"https://github.com/MarkUsProject/Markus/security/advisories/GHSA-p5pc-pxrj-3893","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/MarkUsProject/Markus/commit/55d74f2ddb72d2ec2f29aa2b4cb6b2da10755036","name":"https://github.com/MarkUsProject/Markus/commit/55d74f2ddb72d2ec2f29aa2b4cb6b2da10755036","tags":["x_refsource_MISC"]},{"url":"https://github.com/MarkUsProject/Markus/releases/tag/v2.9.1","name":"https://github.com/MarkUsProject/Markus/releases/tag/v2.9.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-05T20:06:13.433Z"},"source":{"advisory":"GHSA-p5pc-pxrj-3893","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-06T17:03:57.120331Z","id":"CVE-2026-28405","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-06T17:04:05.190Z"}}]}}}