{"cve":"CVE-2026-57191","nvd":{"published":"2026-10-27T22:17:27.390","modified":"2026-10-27T22:17:27.390","status":"Received","description":"Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, an unbounded `sscanf` in `res_pjsip_pubsub` when parsing the `MWI NOTIFY` `Message-Account` field may allow an unauthenticated attacker to send a carefully crafted packet that causes a stack buffer overflow and corrupts the underlying transport, permanently disabling all SIP functionality. An Asterisk restart is required to restore full operation. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.2},"cvss_v3":null,"cwes":["CWE-120","CWE-787"],"references":["https://github.com/asterisk/asterisk/commit/0e89514084490070c5ecee419ec5ee37b7c49528","https://github.com/asterisk/asterisk/commit/647b35c3cfd4a2cc3b1fb7560b085feba5c24b4b","https://github.com/asterisk/asterisk/commit/7a1ffcdf38cc76d1c4eae51651667f3fd4548ab0","https://github.com/asterisk/asterisk/commit/b4be3bd67ce4ac35b94fbfa860cdd9e1c906610b","https://github.com/asterisk/asterisk/commit/b5281828dad7d44658439ba6393fe6be3328a4bd"],"products":[],"source":"nvd","synced_at":"2026-10-27T22:38:42.705297859+00:00"},"epss":null,"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}