# CVE-2026-104433: Mooncake transfer engine out-of-bounds read in readString

Source: https://junglewise.ai/threats/cve-2026-104433-mooncake-transfer-engine-before-0-3-12-contains-an-out-of-bounds  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-03. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-104433 · Severity: high · CVSS 7.5 · Published 2026-10-03

Mooncake transfer engine is a component used to serve AI models like Kimi LLM. An unauthenticated attacker can crash the service by sending a specially crafted zero-length handshake frame to the listening port, causing denial of service to dependent inference servers.

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

## Quick answers

**Is CVE-2026-104433 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104433 being exploited in the wild.

**How severe is CVE-2026-104433?** High severity, with a CVSS score of 7.5, published 3 October 2026.

**Which products and versions are affected?** Moonshot AI Mooncake transfer engine before 0.3.12.

**Is there a fix for CVE-2026-104433?** Yes: fixed in 0.3.12. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-104433 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-104433?** 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.

## How to fix

- Fixed in 0.3.12

## Technical details

The readString function in include/common.h fails to validate frame length before buffer access, allowing an out-of-bounds read when zero-length handshake frames are received. The vulnerability is unauthenticated and requires only network access to the handshake port; sending an eight-byte frame triggers a crash of the hosting process.

## Affected products

- Moonshot AI Mooncake transfer engine before 0.3.12

## Timeline

- 2026-10-03: disclosed
- 2026-10-03: patched: Fix included guard on readString against zero-length network input

## References

- [https://github.com/kvcache-ai/Mooncake](https://github.com/kvcache-ai/Mooncake)
- [https://github.com/kvcache-ai/Mooncake/commit/c142b40590259360196d8e504b2193382529e7b4](https://github.com/kvcache-ai/Mooncake/commit/c142b40590259360196d8e504b2193382529e7b4)

## Related threats

- [Mooncake transfer engine memory exhaustion in receivePeerNotify](https://junglewise.ai/threats/cve-2026-103761-mooncake-transfer-engine-through-0-3-13-post1-contains-a-memory)