CVE-2026-57187 asterisk CVE debrief

Who should care

Telephony administrators and security teams responsible for Asterisk installations should assess exposure and prioritize patching to prevent potential disruptions caused by this heap-use-after-free issue in `PJSIP TCP/SDP` handling. They should verify Asterisk versions, apply patches, and monitor for exploitation attempts.

Why it matters

CVE-2026-57187 is a vulnerability in Asterisk that can cause a heap-use-after-free in `PJSIP TCP/SDP` handling. Telephony administrators and security teams should assess exposure and prioritize patching to prevent potential disruptions.

• Potential disruption to telephony services
• Need to verify Asterisk version and apply patches
• Possible exploitation attempts require monitoring

Technical summary

The vulnerability can be triggered by sending a SIP INVITE over a connection-oriented transport and disconnecting before Asterisk responds with the 200 OK. This issue has been fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3. Telephony administrators and security teams should assess exposure and prioritize patching to prevent potential disruptions caused by heap-use-after-free in `PJSIP TCP/SDP` handling. Affected systems require immediate attention to prevent exploitation.

Defensive priority

Telephony administrators should prioritize patching Asterisk installations to prevent potential disruptions.

Recommended defensive actions

• Apply patches to Asterisk installations
• Review and update Asterisk versions to 20.20.1, 21.12.3, 22.10.1, 23.4.1 or Certified Asterisk 20.7-cert11, 22.8-cert3
• Monitor Asterisk logs for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability was introduced in Asterisk and can be triggered by sending a SIP INVITE over a connection-oriented transport. The issue has been fixed in multiple versions of Asterisk. This heap-use-after-free issue in `PJSIP TCP/SDP` handling requires verification of Asterisk versions and application of patches to prevent potential disruptions. Evidence is limited, and defenders should verify affected scope and apply patches.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.