# CVE-2026-57160: PJSIP: SIP message header buffer overflow

> A buffer overflow in PJSIP allows remote attackers to write one byte past the buffer end, potentially causing crashes in SIP proxies or SBCs.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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-2026-57160, GHSA-277r-3q2j-mxcw, UBUNTU-CVE-2026-57160

## What is CVE-2026-57160?

CVE-2026-57160 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 d6a0e7f, a buffer overflow can occur in pjsip_generic_array_hdr_print() in pjsip/src/pjsip/sip_msg.c, the function that serializes generic array headers (such as Allow, Require, Supported, and Unsupported). Under certain output-buffer boundary conditions the function can write one byte past the end of the buffer. This is reachable mainly in applications that parse and re-serialize incoming SIP requests — for example a proxy, SBC, or B2BUA — where a remote peer can influence the serialized message. The out-of-bounds write is a single fixed byte; code execution and information disclosure are not demonstrated, and in typical pool-based allocations the byte falls within allocation slack. This issue has been patched via commit d6a0e7f.

Weakness: CWE-193 (Off-by-one Error)

## Which versions are affected by CVE-2026-57160?

It affects 1 product.


Products: Teluu Pjsip.

## How do I fix CVE-2026-57160?

No fix has been published for CVE-2026-57160 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57160 being exploited?

There is no known exploitation of CVE-2026-57160 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-2026-57160 and fix it if it is affected.

What it is: CVE-2026-57160 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-2026-57160 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-2026-57160/ (Markdown: https://insights.sbomify.com/CVE-2026-57160/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57160
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57160
- OSV: https://osv.dev/vulnerability/CVE-2026-57160

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57160/
Summaries are generated and may contain mistakes; the official description above is the record.