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Vulnerability record · CVE-2026-57166 · published 4 September 2026

CVE-2026-57166: Teluu pjsip stack-based buffer overflow vulnerability

Teluu · Pjsip

PJSIP is a free and open source multimedia communication library written in C. Prior to commit 4472a31, a stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when rendering feedback for an entered command line. Several command-line handling paths write an attacker-influenced amount of data into fixed-size buffers without sufficient bounds checking, so a long command line can overflow them. This affects only applications that enable the telnet CLI front-end (e.g. pj_cli_telnet_create() / --cli-telnet-port). The telnet CLI is an interactive administration interface with no authentication, so any client able to reach it can already issue arbitrary CLI commands. A malformed or overly long command line can overflow a fixed-size stack buffer while rendering command-line feedback, which may lead to application termination. Because reaching this code already requires access to the unauthenticated CLI, the impact beyond that existing access is limited. Applications that do not enable the telnet CLI front-end are not affected. This issue has been patched via commit 4472a31.

6.3 CVSS 4.0 Medium EPSS 0.53% · top 57.0% CWE-121 · Stack-based buffer overflow
6.3CVSS 4.0 base score
0.53%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
11 Sep 2026Last modified by NVD

Description

PJSIP is a free and open source multimedia communication library written in C. Prior to commit 4472a31, a stack buffer overflow exists in the PJLIB-UTIL telnet CLI front-end when rendering feedback for an entered command line. Several command-line handling paths write an attacker-influenced amount of data into fixed-size buffers without sufficient bounds checking, so a long command line can overflow them. This affects only applications that enable the telnet CLI front-end (e.g. pj_cli_telnet_create() / --cli-telnet-port). The telnet CLI is an interactive administration interface with no authentication, so any client able to reach it can already issue arbitrary CLI commands. A malformed or overly long command line can overflow a fixed-size stack buffer while rendering command-line feedback, which may lead to application termination. Because reaching this code already requires access to the unauthenticated CLI, the impact beyond that existing access is limited. Applications that do not enable the telnet CLI front-end are not affected. This issue has been patched via commit 4472a31.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-38703Teluu pjsip use after free vulnerabilityPJSIP is a free and open source multimedia communication library written in C with high level API in C, C++, Java, C#, and Python languages. SRTP is …EPSS 1.3%9.8CVE-2022-23537Teluu pjsip heap-based buffer overflow vulnerabilityPJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, S…EPSS 1.1%9.8CVE-2022-31031Teluu pjsip classic buffer overflow vulnerabilityPJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, S…EPSS 2.0%9.8CVE-2022-24754Teluu pjsip classic buffer overflow vulnerabilityPJSIP is a free and open source multimedia communication library written in C language. In versions prior to and including 2.12 PJSIP there is a stac…EPSS 2.1%9.8CVE-2022-23608Teluu pjsip use after free vulnerabilityPJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, S…EPSS 4.0%9.8CVE-2021-43300Teluu pjsip stack-based buffer overflow vulnerabilityStack overflow in PJSUA API when calling pjsua_recorder_create. An attacker-controlled 'filename' argument may cause a buffer overflow since it is co…EPSS 2.4%9.8CVE-2021-43303Teluu pjsip classic buffer overflow vulnerabilityBuffer overflow in PJSUA API when calling pjsua_call_dump. An attacker-controlled 'buffer' argument may cause a buffer overflow, since supplying an o…EPSS 2.4%9.8CVE-2021-43301Teluu pjsip stack-based buffer overflow vulnerabilityStack overflow in PJSUA API when calling pjsua_playlist_create. An attacker-controlled 'file_names' argument may cause a buffer overflow since it is …EPSS 2.4%

Source: NIST National Vulnerability Database (record CVE-2026-57166), CISA KEV, FIRST EPSS (scores of 2026-10-03). This page is refreshed as NVD updates the record.