CVE-2026-57160
Received Received - Intake

Buffer Overflow in PJSIP SIP Message Serialization

Publication date: 2026-09-04

Last updated on: 2026-09-04

Assigner: GitHub, Inc.

Description
PJSIP is a free and open source multimedia communication library written in C. Prior to commit d6a0e7f, a buffer overflow can occur in pjsip_generic_array_hdr_print() in pjsip/src/pjsip/sip_msg.c, the function that serializes generic array headers (such as Allow, Require, Supported, and Unsupported). Under certain output-buffer boundary conditions the function can write one byte past the end of the buffer. This is reachable mainly in applications that parse and re-serialize incoming SIP requests — for example a proxy, SBC, or B2BUA — where a remote peer can influence the serialized message. The out-of-bounds write is a single fixed byte; code execution and information disclosure are not demonstrated, and in typical pool-based allocations the byte falls within allocation slack. This issue has been patched via commit d6a0e7f.

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Meta Information

Published
2026-09-04
Last Modified
2026-09-04
Generated
2026-09-05
AI Q&A
2026-09-04
EPSS Evaluated
N/A
NVD
CVE-2026-57160
EUVD
EUVD-2026-71654

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
pjsip pjsip to d6a0e7f (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-193 A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

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Executive Summary

This vulnerability is a buffer overflow in PJSIP, a multimedia communication library. It occurs in the function pjsip_generic_array_hdr_print() which serializes certain SIP headers. Under specific buffer boundary conditions, the function writes one byte past the end of the allocated buffer. This is mainly exploitable in applications that parse and re-serialize incoming SIP requests, such as proxies or B2BUAs, where a remote attacker could influence the serialized message.

Detection Guidance

Detection involves checking if your system uses a vulnerable version of PJSIP. Inspect the installed version with commands like 'pjsip --version' or 'apt show libpjsip2' (Debian/Ubuntu) or 'rpm -qi pjsip' (RHEL). Compare the version against the patched commit d6a0e7f. Monitor SIP traffic for malformed headers or crashes during serialization.

Impact Analysis

The impact is limited as the out-of-bounds write is a single fixed byte. Code execution and information disclosure are not demonstrated. In typical memory allocations, the extra byte may fall within slack space, reducing risk. However, in edge cases, it could cause crashes or unexpected behavior in affected applications like proxies or SBCs.

Compliance Impact

This vulnerability may impact compliance with standards like GDPR and HIPAA by potentially allowing unauthorized data modification or exposure. The buffer overflow could lead to memory corruption, which might compromise data integrity or confidentiality in systems handling sensitive information.

Mitigation Strategies

Update PJSIP to the latest patched version that includes commit d6a0e7f. If immediate updates are not possible, restrict network access to SIP services or use firewalls to limit exposure. Review and test SIP proxy, SBC, or B2BUA configurations to ensure they handle malformed headers safely.

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