{"id":"CVE-2026-103858","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-103858","generatedAt":"2026-10-28T01:12:36.801Z","title":"As a result, an authenticated user who is outside the relevant sharing group or who does not have visibility on the associated event could: - Read the thread title and the content of the quoted post - Submit a new post into the discussion thread This…","description":"MISP contains an incomplete authorization check in the discussion posting functionality. When a user submits a post to a thread or replies to an existing post, the application only verified whether the target thread was restricted to a single organization (org-only distribution). It did not enforce the full thread access control list, including sharing-group membership and event-level visibility.\n\nAs a result, an authenticated user who is outside the relevant sharing group or who does not have visibility on the associated event could:\n\n- Read the thread title and the content of the quoted post\n\n- Submit a new post into the discussion thread\n\nThis constitutes both an information disclosure (reading restricted thread and post content) and an integrity issue (injecting content into a thread the user is not authorized to participate in).\n\nAffected: <2.5.48","published":"2026-10-01T12:17:16.000Z","lastModified":"2026-10-01T15:17:30.000Z","status":"Deferred","sourceIdentifier":"5a6e4751-2f3f-4070-9419-94fb35b644e8","cvss":{"version":"4.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-285"],"affected":[],"epss":{"score":0.00219,"percentile":0.12267,"date":"2026-10-26","history":[{"date":"2026-10-02","score":0.00219,"percentile":0.11179}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-01T12:17:16.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-10-01T12:17:16.080Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://github.com/MISP/MISP/commit/79fbd4c75","source":"5a6e4751-2f3f-4070-9419-94fb35b644e8"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-103858","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}