--- title: "CVE-2026-57191: Asterisk - Buffer Overflow" description: "Asterisk < 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk < 20.7-cert11, 22.8-cert3 contain a stack buffer overflow caused by unbounded sscanf in res_pjsip_pubsub parsing MWI NOTIFY Message-Account field, letting unauthenticated attackers disable SIP functionality, exploit requires crafted packet." url: https://panop.io/threat-heartbeat/CVE-2026-57191/ --- # CVE-2026-57191 Asterisk - Buffer Overflow Asterisk < 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk < 20.7-cert11, 22.8-cert3 contain a stack buffer overflow caused by unbounded sscanf in res\_pjsip\_pubsub parsing MWI NOTIFY Message-Account field, letting unauthenticated attackers disable SIP functionality, exploit requires crafted packet. CVSS base score 8.2 /10 High CISA KEV Not listed Public exploit None known Authentication Not required EPSS 0.59% chance of exploitation in 30 days [View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-57191) ## Details Type Buffer Overflow Impact Denial Of Service CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Published 27 October 2026 Updated 29 October 2026 Weakness [CWE-120](https://cwe.mitre.org/data/definitions/120.html) ## Vendor fix Update to versions 20.20.1, 21.12.3, 22.10.1, 23.4.1 or Certified Asterisk 20.7-cert11, 22.8-cert3 or later. Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them. ## References - [https://nvd.nist.gov/vuln/detail/CVE-2026-57191](https://nvd.nist.gov/vuln/detail/CVE-2026-57191) - [https://github.com/asterisk/asterisk/commit/b4be3bd67ce4ac35b94fbfa860cdd9e1c906610b](https://github.com/asterisk/asterisk/commit/b4be3bd67ce4ac35b94fbfa860cdd9e1c906610b) - [https://github.com/asterisk/asterisk/releases/tag/22.10.1](https://github.com/asterisk/asterisk/releases/tag/22.10.1) - [https://github.com/asterisk/asterisk/commit/647b35c3cfd4a2cc3b1fb7560b085feba5c24b4b](https://github.com/asterisk/asterisk/commit/647b35c3cfd4a2cc3b1fb7560b085feba5c24b4b) - [https://github.com/asterisk/asterisk/commit/ee1b66a5e40733ba0b9fad7fc4d032cabbe1dd75](https://github.com/asterisk/asterisk/commit/ee1b66a5e40733ba0b9fad7fc4d032cabbe1dd75) - [https://github.com/asterisk/asterisk/releases/tag/21.12.3](https://github.com/asterisk/asterisk/releases/tag/21.12.3) - [https://github.com/asterisk/asterisk/releases/tag/23.4.1](https://github.com/asterisk/asterisk/releases/tag/23.4.1) - [https://github.com/asterisk/asterisk/tree/24.0.0-pre1](https://github.com/asterisk/asterisk/tree/24.0.0-pre1) - [https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11](https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11) - [https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3](https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3) - [https://github.com/asterisk/asterisk/security/advisories/GHSA-589g-qgf8-m6mx](https://github.com/asterisk/asterisk/security/advisories/GHSA-589g-qgf8-m6mx) - [https://github.com/asterisk/asterisk/commit/7a1ffcdf38cc76d1c4eae51651667f3fd4548ab0](https://github.com/asterisk/asterisk/commit/7a1ffcdf38cc76d1c4eae51651667f3fd4548ab0) - [https://github.com/asterisk/asterisk/commit/b5281828dad7d44658439ba6393fe6be3328a4bd](https://github.com/asterisk/asterisk/commit/b5281828dad7d44658439ba6393fe6be3328a4bd) - [https://github.com/asterisk/asterisk/commit/dca516f6d895e8867d48fa56b6ce7f05b6f7457a](https://github.com/asterisk/asterisk/commit/dca516f6d895e8867d48fa56b6ce7f05b6f7457a) - [https://github.com/asterisk/asterisk/releases/tag/20.20.1](https://github.com/asterisk/asterisk/releases/tag/20.20.1) - [https://github.com/asterisk/asterisk/commit/0e89514084490070c5ecee419ec5ee37b7c49528](https://github.com/asterisk/asterisk/commit/0e89514084490070c5ecee419ec5ee37b7c49528) [← All CVEs](https://panop.io/threat-heartbeat/) ## What this record can't tell you - Whether you run the affected software, and where - Whether an attacker can actually reach and exploit it - The misconfigurations that never get a CVE number - What it would cost the business, ranked into what to fix first Panop answers these inside your environment, for this CVE and every other finding. [Book a demo](https://panop.io/demo)