{"id":"CVE-2026-49140","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-49140","generatedAt":"2026-10-28T05:59:21.371Z","title":"Nanobot prior to version 0.2.1 contains a denial of service vulnerability in the Matrix channel media download handler that allows authenticated room members to exhaust process memory and bandwidth by sending media events with missing or invalid size…","description":"Nanobot prior to version 0.2.1 contains a denial of service vulnerability in the Matrix channel media download handler that allows authenticated room members to exhaust process memory and bandwidth by sending media events with missing or invalid size metadata. Attackers can send multiple concurrent Matrix media events with omitted or invalid declared sizes to trigger simultaneous large media downloads that fully materialize response bodies before post-download rejection, consuming process resources until service degradation occurs.","published":"2026-06-01T21:16:47.000Z","lastModified":"2026-07-22T08:10:00.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/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-770"],"affected":[],"epss":{"score":0.00268,"percentile":0.18851,"date":"2026-10-27","history":[]},"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 (0.27%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/HKUDS/nanobot/commit/1d4000560dfff1acb83f5c5ca8ef3ab1f092bd14","source":"disclosure@vulncheck.com"},{"url":"https://github.com/HKUDS/nanobot/pull/4106","source":"disclosure@vulncheck.com"},{"url":"https://github.com/HKUDS/nanobot/releases/tag/v0.2.1","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nanobot-denial-of-service-via-matrix-media-download-handler","source":"disclosure@vulncheck.com"},{"url":"https://github.com/HKUDS/nanobot/pull/4106","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-49140","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."}