CVE-2026-57161 PJSIP: Stack overflow handling Service-Route headers in a registration response
A stack buffer overflow in PJSIP allows a malicious registrar to cause application termination via excessive Service-Route headers.
- 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-2026-57161?
CVE-2026-57161 is a high-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 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.
Weakness: CWE-121
Which versions are affected by CVE-2026-57161?
It affects 1 product.
Products include Teluu Pjsip.
How do I fix CVE-2026-57161?
No fix has been published for CVE-2026-57161 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-2026-57161 being exploited?
There is no known exploitation of CVE-2026-57161 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-2026-57162 PJSIP: Stack overflow parsing SDP a=crypto attributes
- CVE-2026-57163 PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend
- CVE-2026-57159 PJSIP: SDP parser out-of-bounds write in remote payload-type map maintenance
Sources
Also known as DEBIAN-CVE-2026-57161, GHSA-xc62-j9h2-mp84, UBUNTU-CVE-2026-57161.