CVE-2026-103764: kvcache-ai Mooncake

Mooncake transfer engine before 0.3.13 Unauthenticated Arbitrary Memory Read/Write via TCP Transport

CVSS 9.3 CriticalCriticalEPSS 0.0082 · 57th percentile

Critical, because:

CVSS score 9.3: 9.0 or more.

Published by the CVE Program (CNA: VulnCheck) at 1 Oct 2026, 23:19 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
kvcache-ai	Mooncake pkg:pypi/mooncake-transfer-engine	affected before 0.3.13 custom Other versions: unaffected

Identifiers

CVE-2026-103764

CNA

VulnCheck

Weakness (CWE)

CWE-822

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.3	Critical	4.0	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	CNA (VulnCheck)Used for this record
9.8	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0082, the 57th percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 1 Oct 2026. New records show when each source confirmed them.

Sources

References from the CNA

github.com/kvcache-ai/Mooncake/issues/4441 issue-tracking
github.com/kvcache-ai/Mooncake/commit/a2933849417259e562fc9cbad63c618d464dfb2d patch
github.com/kvcache-ai/Mooncake/releases/tag/v0.3.13 release-notes
github.com/kvcache-ai/Mooncake/blob/6041a609a8c3af35e778f70db344f145c2914980/mooncake-transfer-engine/src/transport/tcp_transport/tcp_transport.cpp#L209 technical-description
github.com/kvcache-ai/Mooncake product
www.vulncheck.com/advisories/mooncake-transfer-engine-before-0.3.13-unauthenticated-arbitrary-memory-read-write-via-tcp-transport third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.