---
id: CVE-2026-57164
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 8d5956a, a heap buffer overflow exists in the PJLIB-UTIL HTTP
  client (http_client.c) when buffering an HTTP response body. This affects
  applic…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-122
vendor: teluu
product: pjsip
affected:
  - pjsip <= 2.17
published: '2026-09-04'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T15:53:18.427'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-57164'
references:
  - url: >-
      https://github.com/pjsip/pjproject/commit/8d5956afab2ede95ddb199078dc19a8ac0114f3d
    label: security-advisories@github.com
  - url: 'https://github.com/pjsip/pjproject/security/advisories/GHSA-59fr-724j-6fjv'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57164.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-57164'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-57164'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00451
epssPercentile: 0.36679
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-08T17:38:19.222679Z'
scores:
  nvd: 5.9
  cna: 8.3
  vendor: 7.4
ingestedAt: '2026-09-08T18:07:34.885Z'
---

## Overview

PJSIP is a free and open source multimedia communication library written in C. Prior to commit 8d5956a, a heap buffer overflow exists in the PJLIB-UTIL HTTP client (http_client.c) when buffering an HTTP response body. This affects applications that use the PJLIB-UTIL HTTP client to receive a whole response body at once (a completion callback with no incremental on_data_read callback). When growing the response buffer, an incorrect size calculation based on the server-supplied Content-Length can leave the buffer too small, causing response data to be written past the end of the allocation. A malicious or man-in-the-middle HTTP server can trigger this with a crafted response; impact may range from unexpected application termination to memory corruption. Applications that consume the response incrementally (via on_data_read), or that only connect to trusted servers, are not affected. This issue has been patched via commit 8d5956a.

## 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-2026-57164.json)