How severe is CVE-2026-103761?

No CVSS score has been assigned to CVE-2026-103761 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-103761?

Affected package information for CVE-2026-103761 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-103761?

Upgrade the affected component to the fixed release for CVE-2026-103761, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-103761 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-103761 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-103761 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-103761 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-103761?

CVE-2026-103761 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 28th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-103761?

CVE-2026-103761 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-103761 published, and has it been updated?

CVE-2026-103761 was published on October 1, 2026 and was last updated on October 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-103761: mooncake

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-103761.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs28th percentile — riskier than 28% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

Mooncake transfer engine through 0.3.13.post1 contains a memory exhaustion vulnerability in TransferMetadata::receivePeerNotify that allows unauthenticated attackers to grow process memory without limit. Attackers can repeatedly send notify frames up to 1 MB to the handshake RPC port, filling the uncapped notifys vector until the out-of-memory killer terminates the engine.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-103761, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

Mooncake transfer engine through 0.3.13.post1 contains a memory exhaustion vulnerability in TransferMetadata::receivePeerNotify that allows unauthenticated attackers to grow process memory without limit. Attackers can repeatedly send notify frames up to 1 MB to the handshake RPC port, filling the uncapped notifys vector until the out-of-memory killer terminates the engine.

O3 Security · Impact-Aware SCA

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CVE-2026-103761 — mooncake