What’s Vulnerable › Vulnerabilities

CVE-2026-57191: Asterisk: Stack buffer overflow in MWI NOTIFY Message-Account parsing

• Severity: high (CVSS 8.2 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-27 · updated 2026-10-28
• Weakness: CWE-120

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.

Affected products

• asterisk: before 20.20.1; from 21.0.0-pre1, < 21.12.3; from 22.0.0-pre1, < 22.10.1; from 23.0.0-pre1, < 23.4.1
• asterisk certified-asterisk: before 20.7-cert11; from 22.8-cert1-pre1, < 22.8-cert3

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
• https://github.com/asterisk/asterisk/commit/dca516f6d895e8867d48fa56b6ce7f05b6f7457a
• https://github.com/asterisk/asterisk/commit/ee1b66a5e40733ba0b9fad7fc4d032cabbe1dd75
• https://github.com/asterisk/asterisk/releases/tag/20.20.1
• https://github.com/asterisk/asterisk/releases/tag/21.12.3
• https://github.com/asterisk/asterisk/releases/tag/22.10.1
• https://github.com/asterisk/asterisk/releases/tag/23.4.1
• https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11

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