# CVE-2026-116775: pageant: unbounded frame buffering on peer-controlled 4-byte length prefix (memory-exhaustion DoS)


- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** GHSA-662x-8wvj-2276

## What is CVE-2026-116775?

CVE-2026-116775 is a low-severity vulnerability in Eugeny russh, published on 27 Oct 2026. 

### Official description

pageant provides a PageantStream type that implements AsyncRead and AsyncWrite traits and can be used to communicate with a running Pageant instance. From 0.2.0 until 0.2.5, PageantStream::new in pageant/src/wmmessage.rs trusts a peer-controlled four-byte length prefix and buffers until len + 4 bytes are available without checking the fixed _AGENT_MAX_MSGLEN transport capacity. An application that bridges an SSH forwarded-agent channel to the raw stream can allow a malicious server to force large allocations or retain a partially filled frame, causing client memory exhaustion. This issue is fixed in version 0.2.5.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-116775?


## How do I fix CVE-2026-116775?

No fix has been published for CVE-2026-116775 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-116775 being exploited?

There is no known exploitation of CVE-2026-116775 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-116775 and fix it if it is affected.

What it is: CVE-2026-116775 is a low-severity vulnerability in Eugeny russh, published on 27 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-116775 in the wild and no public exploit code.

Affected product: Eugeny russh. 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-2026-116775/ (Markdown: https://insights.sbomify.com/CVE-2026-116775/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116775
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116775
- OSV: https://osv.dev/vulnerability/CVE-2026-116775

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-116775/
Summaries are generated and may contain mistakes; the official description above is the record.