# CVE-2026-57159: PJSIP: SDP parser out-of-bounds write in remote payload-type map maintenance

> A remote attacker can trigger memory corruption and denial of service in PJSIP via crafted SDP messages if the remote payload-type map maintenance feature is enabled.

- **Severity:** High 8.4 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/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-2026-57159, GHSA-rfwg-w9gq-9mw2, UBUNTU-CVE-2026-57159

## What is CVE-2026-57159?

CVE-2026-57159 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 673b978, a remote out-of-bounds read and write can occur in the SDP negotiator when the remote payload-type map maintenance feature is enabled. assign_pt_and_update_map() in pjmedia/src/pjmedia/sdp_neg.c uses payload-type numbers taken from a remote SDP offer or answer to index fixed-size internal tables without sufficient bounds validation, so a crafted remote SDP can cause memory access outside those tables. The practical impact is memory corruption and denial of service; code execution is not demonstrated. This path is only reached when PJMEDIA_SDP_NEG_MAINTAIN_REMOTE_PT_MAP is enabled. The default is disabled, so default builds are not affected; the feature is an interoperability option that integrating products may enable. This issue has been patched via commit 673b978.

Weakness: CWE-787 (Out-of-bounds Write), CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2026-57159?

It affects 1 product.


Products: Teluu Pjsip.

## How do I fix CVE-2026-57159?

No fix has been published for CVE-2026-57159 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57159 being exploited?

There is no known exploitation of CVE-2026-57159 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-2026-57159 and fix it if it is affected.

What it is: CVE-2026-57159 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.
Exploitation: There is no known exploitation of CVE-2026-57159 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-2026-57159/ (Markdown: https://insights.sbomify.com/CVE-2026-57159/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57159
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57159
- OSV: https://osv.dev/vulnerability/CVE-2026-57159

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57159/
Summaries are generated and may contain mistakes; the official description above is the record.