---
id: CVE-2026-57165
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 628b716, a stack buffer overflow exists in the PJLIB-UTIL
  telnet CLI front-end when redrawing the command line during history recall
  (handle_u…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-121
vendor: teluu
product: pjsip
affected:
  - pjsip <= 2.17
published: '2026-09-04'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T16:53:20.417'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-57165'
references:
  - url: >-
      https://github.com/pjsip/pjproject/commit/628b71638465bacf66e767959e6acbab822eccd6
    label: security-advisories@github.com
  - url: 'https://github.com/pjsip/pjproject/security/advisories/GHSA-rpq9-9fx7-95xw'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57165.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-57165'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-57165'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00452
epssPercentile: 0.36635
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T16:37:27.737615Z'
scores:
  nvd: 5.3
  cna: 6.3
  vendor: 7.5
ingestedAt: '2026-09-08T18:07:34.889Z'
---

## Overview

PJSIP is a free and open source multimedia communication library written in C. Prior to commit 628b716, a stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when redrawing the command line during history recall (handle_up_down() in cli_telnet.c). This affects only applications that enable the telnet CLI front-end (same gating as the related CLI issue). The line-redraw sequence for a recalled history entry can accumulate more data than a fixed-size stack buffer holds, which may lead to application termination. Exploitation requires access to the unauthenticated telnet CLI, which already permits arbitrary CLI commands, so the additional impact is limited. Applications that do not enable the telnet CLI front-end are not affected. This issue has been patched via commit 628b716.

## 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-2026-57165.json)