CVE-2026-57165 PJSIP: Pre-authentication overflow in the telnet CLI history
A stack buffer overflow in the PJSIP telnet CLI history recall can cause application termination, requiring the telnet CLI to be enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-57165?
CVE-2026-57165 is a medium-severity memory corruption vulnerability in pjsip pjproject, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-121
Which versions are affected by CVE-2026-57165?
It affects 1 product.
Products include Teluu Pjsip.
How do I fix CVE-2026-57165?
No fix has been published for CVE-2026-57165 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-57165 being exploited?
There is no known exploitation of CVE-2026-57165 in the wild and no public exploit code.
Other vulnerabilities in pjsip pjproject
- CVE-2023-38703 PJSIP has use-after-free vulnerability in SRTP media transport
- CVE-2022-39269 Media transport downgrade from the secure version (SRTP) to non-secure (RTP) in pjsip
- CVE-2026-57161 PJSIP: Stack overflow handling Service-Route headers in a registration response
- CVE-2026-57162 PJSIP: Stack overflow parsing SDP a=crypto attributes
- CVE-2026-57163 PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend
Sources
Also known as DEBIAN-CVE-2026-57165, GHSA-rpq9-9fx7-95xw, UBUNTU-CVE-2026-57165.