CVE-2026-57163

Published Sep 4, 2026

Last updated 10 days ago

CVSS high 8.8

Overview

Description
PJSIP is a free and open source multimedia communication library written in C. Prior to commit c4a151a, a stack buffer overflow exists in the GnuTLS TLS backend when parsing the Subject Alternative Name extension of a peer certificate (tls_cert_get_info() in ssl_sock_gtls.c). Only GnuTLS builds are affected (--with-gnutls); OpenSSL and Apple SecureTransport/Network.framework builds are not affected. While extracting certificate information after a TLS handshake, an incorrect buffer-size value can cause an oversized SubjectAltName entry to be written past the end of a fixed-size stack buffer. A network-positioned attacker presenting a crafted certificate — a malicious server to a connecting client, or a malicious client to a server that requests certificates — can trigger this during the TLS handshake, before any SIP-level authentication. Impact may range from unexpected application termination to control flow hijack/memory corruption. This issue has been patched via commit c4a151a.
Source
security-advisories@github.com
NVD status
Analyzed
Products
pjsip

Risk scores

CVSS 4.0

Type
Secondary
Base score
8.8
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/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:X/V:X/RE:X/U:X
Severity
HIGH

CVSS 3.1

Type
Primary
Base score
9.1
Impact score
5.2
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Severity
CRITICAL

Weaknesses

security-advisories@github.com
CWE-121

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. 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.•CVE-2026-57166
  2. 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.•CVE-2026-57161
  3. 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.•CVE-2026-57164
  4. 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.•CVE-2026-57165
  5. 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.•CVE-2026-57162

References

Sources include official advisories and independent security research.