{"id":"CVE-2026-66303","aliases":["EUVD-2026-73940","GHSA-g37h-5rqx-hvqg"],"status":"published","title":"Skype for Business and Lync Denial of Service Vulnerability","description":"Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01138,"percentile":0.66993,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-476"],"published":"2026-09-08T18:39:43Z","modified":"2026-11-10T21:38:33Z","products":[{"vendor":"microsoft","product":"skype for business server 2015 cu13"},{"vendor":"microsoft","product":"skype for business server 2019 cu8"},{"vendor":"microsoft","product":"skype for business server subscription edition cu1"},{"vendor":"microsoft","product":"skype_for_business_server"},{"vendor":"microsoft","product":"skype_for_business_server_subscription_edition"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66303","tags":["vendor-advisory","patch","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66303"},{"url":"https://github.com/advisories/GHSA-g37h-5rqx-hvqg"}],"sources":{"cve":[{"id":"CVE-2026-66303","title":"Skype for Business and Lync Denial of Service Vulnerability","description":"Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.","status":"published","published":"2026-09-08T18:39:43.9Z","modified":"2026-11-10T21:38:33.411Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-476"],"updated_at":"2026-11-10T22:48:52.144232Z"}],"euvd":[{"id":"EUVD-2026-73940","description":"Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.","status":"published","published":"2026-09-08T18:39:43Z","modified":"2026-11-10T21:38:33Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-10T23:24:18.784503Z"}],"ghsa":[{"id":"GHSA-g37h-5rqx-hvqg","title":"Null pointer dereference in Skype for Business allows an authorized attacker to deny service over...","description":"Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.","status":"published","published":"2026-09-08T21:34:17Z","modified":"2026-09-08T21:34:26Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T15:11:35.275364Z"}],"nvd":[{"id":"CVE-2026-66303","description":"Null pointer dereference in Skype for Business allows an authorized attacker to deny service over a network.","status":"published","published":"2026-09-08T19:18:07.82Z","modified":"2026-09-16T19:23:02.977Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:12:45.264578Z"}]}}