# 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.

- **Severity:** Medium 6.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Sep 2026
- **Updated:** 8 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-57165, GHSA-rpq9-9fx7-95xw, UBUNTU-CVE-2026-57165

## 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 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-57165?

It affects 1 product.


Products: 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.

## 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](https://insights.sbomify.com/CVE-2023-38703/): PJSIP has use-after-free vulnerability in SRTP media transport (critical 9.8)
- [CVE-2022-39269](https://insights.sbomify.com/CVE-2022-39269/): Media transport downgrade from the secure version (SRTP) to non-secure (RTP) in pjsip (critical 9.1)
- [CVE-2026-57161](https://insights.sbomify.com/CVE-2026-57161/): PJSIP: Stack overflow handling Service-Route headers in a registration response (high 8.8)
- [CVE-2026-57162](https://insights.sbomify.com/CVE-2026-57162/): PJSIP: Stack overflow parsing SDP a=crypto attributes (high 8.8)
- [CVE-2026-57163](https://insights.sbomify.com/CVE-2026-57163/): PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57165 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-57165 in the wild and no public exploit code.

Affected product: pjsip pjproject. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57165/ (Markdown: https://insights.sbomify.com/CVE-2026-57165/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57165
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57165
- OSV: https://osv.dev/vulnerability/CVE-2026-57165

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57165/
Summaries are generated and may contain mistakes; the official description above is the record.