# CVE-2026-103761: Mooncake transfer engine memory exhaustion in receivePeerNotify

Source: https://junglewise.ai/threats/cve-2026-103761-mooncake-transfer-engine-through-0-3-13-post1-contains-a-memory  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-01. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-103761 · Severity: high · CVSS 7.5 · Published 2026-10-01

Mooncake transfer engine is a data transfer platform used in Kimi, an LLM service. Unauthenticated attackers can send specially crafted network packets to the handshake RPC port to exhaust the server's memory without limit, causing a denial of service that terminates the transfer engine process.

Vendors: [Moonshot AI](https://junglewise.ai/threats/vendors/moonshot-ai).

## Quick answers

**Is CVE-2026-103761 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103761 being exploited in the wild.

**How severe is CVE-2026-103761?** High severity, with a CVSS score of 7.5, published 1 October 2026.

**Which products and versions are affected?** Moonshot AI Mooncake transfer engine through 0.3.13.post1.

**Is there a fix for CVE-2026-103761?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-103761 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-103761?** Check whether you run Moonshot AI Mooncake transfer engine at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in the TransferMetadata::receivePeerNotify function, which stores incoming notify frames in an uncapped vector without enforcing size limits. An attacker can repeatedly send up to 1 MB notify frames over the network, causing the vector to grow until the process runs out of memory and is terminated by the out-of-memory killer. No authentication is required to exploit this.

## Affected products

- Moonshot AI Mooncake transfer engine through 0.3.13.post1

## Timeline

- 2026-10-01: disclosed

## References

- [https://github.com/kvcache-ai/Mooncake](https://github.com/kvcache-ai/Mooncake)
- [https://github.com/kvcache-ai/Mooncake/blob/719735896c86b56fabec6cf3e825fb2ea640597a/mooncake-transfer-engine/src/transfer_metadata.cpp](https://github.com/kvcache-ai/Mooncake/blob/719735896c86b56fabec6cf3e825fb2ea640597a/mooncake-transfer-engine/src/transfer_metadata.cpp)

## Related threats

- [Mooncake transfer engine out-of-bounds read in readString](https://junglewise.ai/threats/cve-2026-104433-mooncake-transfer-engine-before-0-3-12-contains-an-out-of-bounds)