CVE-2026-108265 in enclave-os-mini
Summary
by MITRE • 10/09/2026
Enclave OS Mini is a Rust-based runtime for confidential applications inside Intel SGX enclaves. Prior to wasm-v0.40.0, the SGX runtime's RA-TLS challenge certificate path placed the certificate public-key hash and client nonce in quote ReportData but omitted a value bound to the active TLS session. An attacker who obtained an enclave TLS private key could relay a genuine quote onto another connection, causing a relying party to accept an attacker-terminated connection as the attested enclave. This issue is fixed in wasm-v0.40.0.
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Analysis
by VulDB Data Team • 10/09/2026
The vulnerability identified within Enclave OS Mini prior to version 0.40.0 represents a critical flaw in the Remote Attestation Transport Layer Security implementation for applications running inside Intel Software Guard Extensions enclaves. This runtime environment is designed to provide hardware-based isolation, ensuring that confidential data and code remain protected from unauthorized access even if the underlying host operating system or hypervisor is compromised. The core issue stems from an incomplete binding mechanism within the RA-TLS challenge certificate path. Specifically, when generating the quote ReportData, the implementation correctly included the public-key hash of the enclave's certificate and a client nonce to prevent replay attacks on the initial handshake. However, it failed to include any value that was uniquely bound to the active TLS session itself. This omission created a structural gap in the cryptographic binding between the attestation evidence and the specific communication channel established with the relying party.
From an operational perspective, this flaw enables a sophisticated man-in-the-middle attack scenario known as quote relay or session hijacking via certificate reuse. An attacker who has managed to obtain the enclave's TLS private key through compromise of the host environment or other means can exploit this weakness by intercepting a legitimate attestation process. The attacker captures the genuine quote generated by the enclave and relays it onto a different connection where they control both ends, effectively terminating the client-side connection while maintaining an encrypted tunnel with the relying party. Because the quote does not contain session-specific data such as ephemeral keys or channel binding tokens derived from the TLS handshake, the relying party cannot distinguish between the original legitimate session and the relayed one. Consequently, the relying party accepts the attacker-terminated connection as a verified attested enclave, granting the attacker full access to sensitive operations under the guise of authenticity.
This vulnerability aligns with CWE-295 Improper Certificate Validation, specifically regarding the failure to bind certificate validation to the current session context. It also maps closely to MITRE ATT&CK technique T1078 Valid Accounts and potentially T1557 Adversary-in-the-Middle if leveraged in conjunction with other interception capabilities. The impact is severe as it undermines the fundamental trust model of confidential computing, allowing an adversary to impersonate a trusted enclave without needing to break the cryptographic algorithms directly. Instead, they exploit the logical flaw in how identity and session integrity are correlated during the attestation handshake.
The issue was resolved in Enclave OS Mini version 0.40.0 by implementing proper channel binding within the RA-TLS protocol. The fix ensures that values unique to each TLS session, such as ephemeral key material or specific handshake hashes, are included in the quote ReportData. This strengthens the cryptographic linkage between the enclave's identity and the active communication channel, rendering relay attacks ineffective because a captured quote from one session will fail validation when presented on another distinct session due to mismatched binding data. Organizations relying on this runtime should immediately upgrade to version 0.40.0 or later to restore the integrity of remote attestation processes and prevent potential unauthorized access through certificate relaying.