CVE-2026-57161 pjsip CVE debrief

Who should care

Defenders responsible for PJSUA installations, especially those exposed to untrusted registrars or using unprotected transports, should assess their exposure and prioritize patching vulnerable systems.

Why it matters

CVE-2026-57161 is a stack buffer overflow vulnerability in PJSUA that can lead to denial of service and potential memory corruption. Defenders should prioritize verifying and applying patches, especially for installations exposed to untrusted registrars or unprotected transports.

• Denial of service through unexpected application termination
• Potential memory corruption requiring further investigation
• Verification of PJSUA installations for exposure to untrusted registrars or unprotected transports
• Prioritization of patching vulnerable PJSUA installations

Technical summary

The PJSUA library is vulnerable to a stack buffer overflow when processing Service-Route headers in a registration response. This occurs when a registrar returns an excessive number of Service-Route headers, allowing an attacker to write past the end of the array on the stack. The most likely impact is unexpected application termination (denial of service), though memory corruption cannot be excluded.

Defensive priority

Defenders should prioritize verifying and applying patches to vulnerable PJSUA installations, especially those exposed to untrusted registrars or using unprotected transports.

Recommended defensive actions

• Verify PJSUA installations for exposure to untrusted registrars or unprotected transports
• Apply patches to vulnerable PJSUA installations
• Monitor for excessive Service-Route headers in registration responses
• Consider implementing compensating controls for affected applications
• Review and update asset inventory for PJSUA installations
• Track and manage exceptions for PJSUA remediation
• Plan and execute rollback or change windows for PJSUA updates

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, its impact, and available patches. However, the exact scope of affected versions and deployments requires verification from the supplied official sources.

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.