{"id":"CVE-2021-26717","details":"An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.","modified":"2026-07-08T21:26:13.672890Z","published":"2021-02-18T20:15:12.667Z","references":[{"type":"ADVISORY","url":"http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.html"},{"type":"ADVISORY","url":"https://downloads.asterisk.org/pub/security/"},{"type":"ADVISORY","url":"https://downloads.asterisk.org/pub/security/AST-2021-002.html"},{"type":"FIX","url":"http://seclists.org/fulldisclosure/2021/Feb/58"},{"type":"FIX","url":"https://issues.asterisk.org/jira/browse/ASTERISK-29203"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/asterisk/asterisk","events":[{"introduced":"a65908f83e2f17a3aca7eb39c8e06045aca02674"},{"fixed":"3cd8afbdf2c6dffe80c631a5336e21bb1827a5cd"},{"introduced":"5ffe12b6ef30cd503f85d75745fd8d9c2cfafe47"},{"fixed":"fdaf2d0689b7a8928a45019c9af14c53bcdfa6e3"},{"introduced":"2c1bba3cbec008c8ce35c78a2c79f9f207ea58bc"},{"fixed":"332130c4389803a3c7e63cabf00daf5ac66a3068"},{"introduced":"d436f568583184a13aa46349af5a3f0907087b44"},{"last_affected":"10b274d1aba4fc2cf2a8cabcb66eb2a049e2250f"}],"database_specific":{"cpe":["cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:-:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc1:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc2:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc3:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc4:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert2:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert3:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert4:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc1:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc2:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc3:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc4:*:*:*:*:*:*","cpe:2.3:a:digium:certified_asterisk:16.8:cert5:*:*:*:*:*:*"],"extracted_events":[{"introduced":"16.0.0"},{"fixed":"16.16.1"},{"introduced":"17.0.0"},{"fixed":"17.9.2"},{"introduced":"18.0"},{"fixed":"18.2.1"},{"introduced":"16.8-NA"},{"last_affected":"16.8-NA"},{"introduced":"16.8-cert1\\-rc1"},{"last_affected":"16.8-cert1\\-rc1"},{"introduced":"16.8-cert1\\-rc2"},{"last_affected":"16.8-cert1\\-rc2"},{"introduced":"16.8-cert1\\-rc3"},{"last_affected":"16.8-cert1\\-rc3"},{"introduced":"16.8-cert1\\-rc4"},{"last_affected":"16.8-cert1\\-rc4"},{"introduced":"16.8-cert2"},{"last_affected":"16.8-cert2"},{"introduced":"16.8-cert3"},{"last_affected":"16.8-cert3"},{"introduced":"16.8-cert4"},{"last_affected":"16.8-cert4"},{"introduced":"16.8-cert4\\-rc1"},{"last_affected":"16.8-cert4\\-rc1"},{"introduced":"16.8-cert4\\-rc2"},{"last_affected":"16.8-cert4\\-rc2"},{"introduced":"16.8-cert4\\-rc3"},{"last_affected":"16.8-cert4\\-rc3"},{"introduced":"16.8-cert4\\-rc4"},{"last_affected":"16.8-cert4\\-rc4"},{"introduced":"16.8-cert5"},{"last_affected":"16.8-cert5"}],"source":["CPE_RANGE","CPE_STRING"]}}],"versions":["16.8-NA","16.8-cert1\\-rc1","16.8-cert1\\-rc2","16.8-cert1\\-rc3","16.8-cert1\\-rc4","16.8-cert2","16.8-cert3","16.8-cert4","16.8-cert4\\-rc1","16.8-cert4\\-rc2","16.8-cert4\\-rc3","16.8-cert4\\-rc4","16.8-cert5","certified/16.8-cert5","certified/16.8-cert4","certified/16.8-cert4-rc4","certified/16.8-cert4-rc3","certified/16.8-cert4-rc2","certified/16.8-cert4-rc1","certified/16.8-cert3","certified/16.8-cert2","certified/16.8-cert1","certified/16.8-cert1-rc5","certified/16.8-cert1-rc4","certified/16.8-cert1-rc3","certified/16.8-cert1-rc2","certified/16.8-cert1-rc1","16.8.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-26717.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}