{"id":"CVE-2026-103858","title":"MISP contains an incomplete authorization check in the discussion posting functionality","summary":"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 s…","severity":"medium","cvss":5.3,"cvssVector":"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","cwe":["CWE-285"],"vendor":"MISP","product":"MISP","affected":["MISP >= unspecified < 2.5.48"],"published":"2026-10-01","updated":"2026-10-01","sourceUpdated":"2026-10-01T12:17:16.213","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-103858","references":[{"url":"https://github.com/MISP/MISP/commit/79fbd4c75","label":"5a6e4751-2f3f-4070-9419-94fb35b644e8"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-10-01T11:42:53.818Z","slug":"CVE-2026-103858","body":"## Overview\n\nMISP 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\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}