CVE-2026-103764
CVE-2026-103764 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-822.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v4: 9.3
- EPSS exploit prediction: 1% (49th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-822
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-103764?
- 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.
- How severe is CVE-2026-103764?
- CVE-2026-103764 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-103764 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-103764?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2026-103764 published?
- CVE-2026-103764 was published on 2026-10-02.
References
- https://github.com/kvcache-ai/Mooncake
- https://github.com/kvcache-ai/Mooncake/blob/6041a609a8c3af35e778f70db344f145c2914980/mooncake-transfer-engine/src/transport/tcp_transport/tcp_transport.cpp#L209
- https://github.com/kvcache-ai/Mooncake/commit/a2933849417259e562fc9cbad63c618d464dfb2d
- https://github.com/kvcache-ai/Mooncake/issues/4441
- https://github.com/kvcache-ai/Mooncake/releases/tag/v0.3.13
- https://www.vulncheck.com/advisories/mooncake-transfer-engine-before-0.3.13-unauthenticated-arbitrary-memory-read-write-via-tcp-transport
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