# CVE-2026-75883: PPPD buffer overflow in PEAP response code

> A buffer overflow in pppd's PEAP response handling allows a malicious server to corrupt memory, likely causing a crash or denial of service.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** AZL-103302, BELL-CVE-2026-75883, DEBIAN-CVE-2026-75883, GHSA-rwr9-4vx8-vc35, OESA-2026-4116, OESA-2026-4117, OESA-2026-4118, UBUNTU-CVE-2026-75883

## What is CVE-2026-75883?

CVE-2026-75883 is a medium-severity memory corruption vulnerability in ppp, published on 18 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The code in pppd that formats a response to a PEAP Request packet in peap_response() copies an entire TLS record of up to 16384 bytes into the fixed global buffer outpacket_buf
 without checking the available space and without implementing outgoing 
PEAP fragmentation. Thus a pppd process connecting to a server which 
requests PEAP authentication can be induced to corrupt global static 
data following the outpacket_buf array, most likely causing incorrect behavior or a crash.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-75883?


## How do I fix CVE-2026-75883?

Apply the vendor's patch.

## Is CVE-2026-75883 being exploited?

There is no known exploitation of CVE-2026-75883 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-75883 and fix it if it is affected.

What it is: CVE-2026-75883 is a medium-severity memory corruption vulnerability in ppp, published on 18 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-75883 in the wild and no public exploit code.

Affected product: ppp. 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-2026-75883/ (Markdown: https://insights.sbomify.com/CVE-2026-75883/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-75883
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75883
- OSV: https://osv.dev/vulnerability/CVE-2026-75883

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-75883/
Summaries are generated and may contain mistakes; the official description above is the record.