# CVE-2026-103764: Mooncake transfer engine before 0.3.13 Unauthenticated Arbitrary Memory Read/Write via TCP Transport

> Unauthenticated attackers can read or write arbitrary process memory via crafted TCP packets, potentially disclosing secrets or executing code.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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:** 1 Oct 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-mp8g-r7h2-5x36

## What is CVE-2026-103764?

CVE-2026-103764 is a critical memory corruption vulnerability in kvcache-ai Mooncake, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Mooncake transfer engine before 0.3.13 contains an untrusted pointer dereference in ServerSession::readHeader that allows unauthenticated attackers to read and write arbitrary process memory via the TCP transport data port. Attackers can send a crafted SessionHeader with arbitrary addr and size values using READ or WRITE opcodes to disclose KV cache contents, prompts and secrets or corrupt memory toward code execution.

Weakness: CWE-822 (Untrusted Pointer Dereference)

## Which versions are affected by CVE-2026-103764?


## How do I fix CVE-2026-103764?

No fix has been published for CVE-2026-103764 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103764 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103764 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103764 and fix it if it is affected.

What it is: CVE-2026-103764 is a critical memory corruption vulnerability in kvcache-ai Mooncake, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103764 exists.

Affected product: kvcache-ai Mooncake. 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-2026-103764/ (Markdown: https://insights.sbomify.com/CVE-2026-103764/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103764
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103764
- OSV: https://osv.dev/vulnerability/CVE-2026-103764

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103764/
Summaries are generated and may contain mistakes; the official description above is the record.