{"id":"CVE-2021-26906","aliases":["ALPINE-CVE-2021-26906","DEBIAN-CVE-2021-26906","EUVD-2021-13690","GHSA-rjqf-qvfr-v23c"],"status":"published","title":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x,...","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.02547,"percentile":0.85242,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-404"],"published":"2021-02-18T19:50:04Z","modified":"2026-10-24T10:30:49Z","fixes":[{"ecosystem":"Alpine:v3.12","package":"asterisk","fixed_in":["16.16.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.13","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.14","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.15","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.16","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.17","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.18","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.19","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.20","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.21","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.22","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.23","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"asterisk","fixed_in":["18.2.1-r0"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"asterisk","fixed_in":["1:16.16.1~dfsg-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.12","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"16.16.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.13","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.14","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.15","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.16","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.17","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.18","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.19","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.20","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.21","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.22","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"13.0.0"},{"fixed":"18.2.1-r0"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:16.16.1~dfsg-1"}]}],"versions":["0.1.11-3","0.1.11-3woody1","1:1.0.5-2","1:1.0.5-4","1:1.0.6-1","1:1.0.6-2","1:1.0.7-1","1:1.0.7.dfsg.1-1","1:1.0.7.dfsg.1-2","1:1.0.7.dfsg.1-2sarge1","1:1.0.7.dfsg.1-2sarge2","1:1.0.7.dfsg.1-2sarge3","1:1.0.7.dfsg.1-2sarge4","1:1.0.7.dfsg.1-2sarge5","1:1.0.7.dfsg.1-2sarge6","1:1.0.9.dfsg-1","1:1.0.9.dfsg-3","1:1.0.9.dfsg-4","1:1.0.9.dfsg-5","1:1.0.9.dfsg-6","1:1.2.0-beta1.dfsg-1","1:1.2.0-beta2.dfsg-1","1:1.2.0-beta2.dfsg-2","1:1.2.0-beta2.dfsg-3","1:1.2.0-rc1.dfsg-1","1:1.2.0-rc2.dfsg-1","1:1.2.0.dfsg-1","1:1.2.0.dfsg-2","1:1.2.0.dfsg-3","1:1.2.0.dfsg-4","1:1.2.0.dfsg-5","1:1.2.0.dfsg-6","1:1.2.1.dfsg-1","1:1.2.1.dfsg-2","1:1.2.1.dfsg-3","1:1.2.10.dfsg-1","1:1.2.10.dfsg-1bpo1","1:1.2.10.dfsg-2","1:1.2.10.dfsg-3","1:1.2.11.dfsg-1","1:1.2.12.1.dfsg-1","1:1.2.13~dfsg-1","1:1.2.13~dfsg-2","1:1.2.13~dfsg-2etch1","1:1.2.13~dfsg-2etch2","1:1.2.13~dfsg-2etch3","1:1.2.13~dfsg-2etch4","1:1.2.14~dfsg-1","1:1.2.14~dfsg-2","1:1.2.14~dfsg-3","1:1.2.14~dfsg-4","1:1.2.15~dfsg-1","1:1.2.16~dfsg-1","1:1.2.17~dfsg-1","1:1.2.4.dfsg-1","1:1.2.4.dfsg-2","1:1.2.4.dfsg-3","1:1.2.4.df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Advisory","advisory"]},{"url":"http://seclists.org/fulldisclosure/2021/Feb/61","tags":["mailing-list","x_refsource_FULLDISC","x_transferred","Mailing List","Patch","Third Party Advisory","fix"]},{"url":"https://downloads.asterisk.org/pub/security/AST-2021-005.html","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory"]},{"url":"https://issues.asterisk.org/jira/browse/ASTERISK-29196","tags":["x_refsource_CONFIRM","x_transferred","Issue Tracking","Patch","Vendor Advisory","fix"]},{"url":"http://packetstormsecurity.com/files/161477/Asterisk-Project-Security-Advisory-AST-2021-005.html","tags":["x_refsource_MISC","x_transferred","Third Party 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An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2021-02-18T19:50:04Z","modified":"2024-08-03T20:33:41.368Z","updated_at":"2026-11-02T14:32:57.368269Z"}],"euvd":[{"id":"EUVD-2021-13690","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2021-02-18T19:50:04Z","modified":"2024-08-03T20:33:41Z","updated_at":"2026-11-03T03:24:50.84326Z"}],"ghsa":[{"id":"GHSA-rjqf-qvfr-v23c","title":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x,...","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2022-05-24T17:42:37Z","modified":"2023-01-29T05:05:49Z","cwes":["CWE-404"],"updated_at":"2026-11-02T14:45:52.819939Z"}],"nvd":[{"id":"CVE-2021-26906","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2021-02-18T20:15:12.743Z","modified":"2026-06-17T03:43:58.727Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-404"],"updated_at":"2026-11-02T14:06:50.031227Z"}],"osv":[{"id":"ALPINE-CVE-2021-26906","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2021-02-18T20:15:12.743Z","modified":"2026-10-23T17:17:56.163742821Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:27:48.646074Z"},{"id":"CVE-2021-26906","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2021-02-18T20:15:12.743Z","modified":"2026-10-24T10:30:49.70226019Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:18.778776Z"},{"id":"DEBIAN-CVE-2021-26906","description":"An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.","status":"published","published":"2021-02-18T20:15:12.743Z","modified":"2026-10-23T18:02:40.976145397Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:34.637046Z"}]}}