CVE-2026-57162
Received Received - Intake

Stack Buffer Overflow in PJSIP SRTP/SDES Media Transport

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 a1b707c, a stack buffer overflow exists in the SRTP/SDES media transport when processing a=crypto attributes during SDP offer/answer (sdes_encode_sdp() in transport_srtp_sdes.c). This affects applications with SRTP enabled (use_srtp optional or mandatory, using SDES keying). During media negotiation, the crypto attributes from the remote SDP are collected into a fixed-size array without bounding their number; a remote peer that includes an excessive number of a=crypto attributes in a single media description can write past the end of that array on the stack. This is reachable from an incoming SIP INVITE during offer/answer, before application-level authentication. Impact may range from unexpected application termination to control flow hijack/memory corruption. Applications that do not enable SRTP are not affected. This issue has been patched via commit a1b707c.

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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-2026-57162
EUVD
EUVD-2026-71656

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
pjsip pjsip to a1b707c (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-121 A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

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Executive Summary

This vulnerability is a stack buffer overflow in PJSIP, a multimedia communication library. It occurs when processing SDP offer/answer during media negotiation. A remote attacker can send an excessive number of a=crypto attributes in a single media description, causing a buffer overflow in a fixed-size array on the stack. This flaw is reachable during an incoming SIP INVITE before authentication.

Detection Guidance

To detect this vulnerability, monitor for crashes or memory corruption in applications using PJSIP with SRTP enabled during SDP offer/answer processing. Check logs for excessive a=crypto attributes in SDP messages. No specific commands are provided in the context.

Impact Analysis

The impact ranges from unexpected application termination to control flow hijack or memory corruption. Attackers could exploit this to execute arbitrary code or crash the application. Only systems with SRTP enabled (optional or mandatory) are affected; those without SRTP are not vulnerable.

Mitigation Strategies

Apply the patch from commit a1b707c to PJSIP. Disable SRTP if not required. Monitor network traffic for malformed SDP offers with excessive a=crypto attributes. Update to the latest patched version of PJSIP.

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