Bug 2565372 (CVE-2026-57191)

Summary: CVE-2026-57191 asterisk: Asterisk: Denial of Service via stack-based buffer overflow in res_pjsip_pubsub
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Asterisk. An unbounded string parsing vulnerability in the res_pjsip_pubsub module allows an unauthenticated remote attacker to trigger a stack-based buffer overflow by sending a specially crafted Message Waiting Indication (MWI) NOTIFY packet. Successful exploitation leads to a Denial of Service (DoS) by corrupting the network transport and disabling all Session Initiation Protocol (SIP) functionality until the service is restarted.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2565640, 2565641    
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Description OSIDB Bzimport 2026-11-02 19:57:09 UTC
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.