CVE-2026-57160 pjsip CVE debrief

Who should care

Defenders responsible for systems using PJSIP for SIP request parsing and re-serialization should assess exposure and prioritize patching. This includes administrators of proxies, SBCs, B2BUAs, and other network infrastructure relying on PJSIP.

Why it matters

CVE-2026-57160 is a buffer overflow vulnerability in PJSIP's pjsip_generic_array_hdr_print() function. Defenders should care because it affects SIP request parsing and re-serialization, potentially allowing remote influence over serialized messages. The impact is primarily on network infrastructure stability and the need for patch verification.

• Remote influence over serialized SIP messages
• Potential for buffer overflow leading to unexpected behavior
• Need for verification of patch application
• Possible impact on network infrastructure stability

Technical summary

The pjsip_generic_array_hdr_print() function in PJSIP's sip_msg.c can overflow the output buffer by one byte when serializing generic array headers, such as Allow, Require, Supported, and Unsupported. This is primarily a concern for applications that parse and re-serialize SIP requests, like proxies, SBCs, or B2BUAs. The issue has been patched via commit d6a0e7f. Defenders should prioritize verifying and applying patches to affected systems, particularly those using PJSIP for SIP request parsing and re-serialization.

Defensive priority

Defenders should prioritize verifying and applying patches to affected systems, particularly those using PJSIP for SIP request parsing and re-serialization.

Recommended defensive actions

• Verify and apply patches to affected PJSIP systems
• Review and update configurations for SIP request parsing and re-serialization
• Monitor for potential exploitation attempts
• 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
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by a buffer overflow in the pjsip_generic_array_hdr_print() function, which can write one byte past the end of the buffer under certain output-buffer boundary conditions. The issue has been patched via commit d6a0e7f.

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.