---
id: CVE-2026-57161
title: PJSIP is a free and open source multimedia communication library written in C
summary: >-
  PJSIP is a free and open source multimedia communication library written in C.
  Prior to commit acc03b5, a stack buffer overflow exists in PJSUA when
  processing Service-Route headers in a registration response
  (update_service_route() in p…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H'
cwe:
  - CWE-121
vendor: teluu
product: pjsip
affected:
  - pjsip <= 2.17
published: '2026-09-04'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T15:34:41.290'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-57161'
references:
  - url: >-
      https://github.com/pjsip/pjproject/commit/acc03b57cef7a7d31b8e1f5b9117437d7e87c591
    label: security-advisories@github.com
  - url: 'https://github.com/pjsip/pjproject/security/advisories/GHSA-xc62-j9h2-mp84'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57161.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-57161'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-57161'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.0046
epssPercentile: 0.37113
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-09T17:48:03.756748Z'
scores:
  nvd: 8.2
  cna: 8.8
  vendor: 8.2
ingestedAt: '2026-09-08T22:12:30.947Z'
---

## Overview

PJSIP is a free and open source multimedia communication library written in C. Prior to commit acc03b5, a stack buffer overflow exists in PJSUA when processing Service-Route headers in a registration response (update_service_route() in pjsua_acc.c). This affects applications that register using the PJSUA/PJSUA2 account API (the default registration path). The Service-Route URIs from a 2xx response to REGISTER are stored into a fixed-size array without bounding the number of headers; a registrar that returns an excessive number of Service-Route headers can write past the end of the array on the stack. The values written are internal pointers rather than arbitrary data, so the most likely impact is unexpected application termination (denial of service), though memory corruption cannot be excluded. The malicious response may come from a compromised or malicious registrar, or — over unprotected transports — a spoofed response. This issue has been patched via commit acc03b5.

## Affected

- `pjsip <= 2.17`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57161.json)