9.1 CVE Allows Relay Attack on Privasys Enclave OS Mini SGX Runtimes

Privasys released a patch for Enclave OS Mini on Tuesday that addresses a critical security vulnerability allowing identity spoofing through TLS relay attacks. The flaw, tracked as CVE-2026-108265, carries a CVSS score of 9.1, indicating severe risk to systems using the Rust-based runtime for confidential applications within Intel SGX enclaves. According to the National Vulnerability Database, the issue permits an attacker who obtains an enclave TLS private key to relay a genuine quote onto another connection. This manipulation causes relying parties to accept an attacker-terminated connection as the legitimate, attested enclave.

How it unfolded

• Privasys Enclave OS Mini prior to version wasm-v0.40.0 processed RA-TLS challenge certificate paths without binding a value to the active TLS session.
• The SGX runtime placed the certificate public-key hash and client nonce into the quote ReportData, but failed to include the session-specific binding.
• This architectural gap allowed an attacker with the enclave TLS private key to detach a valid quote from its original context and reuse it on a different connection.

Who is affected

System administrators and security teams managing infrastructure that relies on Intel SGX for confidential computing are directly affected by this vulnerability. Any deployment using Privasys Enclave OS Mini versions older than wasm-v0.40.0 is susceptible to remote attestation bypass. The impact is particularly severe for organizations that use these enclaves to process sensitive data or manage critical credentials, as the integrity of the attestation process is compromised. Relying parties that verify enclave identity based on the RA-TLS challenge are at risk of establishing trust with malicious entities masquerading as legitimate enclaves.

What happens next

Privasys has issued wasm-v0.40.0 to resolve CVE-2026-108265. Users must upgrade their Enclave OS Mini installations to this version or later to mitigate the risk. Until the update is applied, the SGX runtime remains vulnerable to relay attacks that exploit the missing TLS session binding. Organizations should verify their current versions immediately and prioritize patching to prevent potential identity theft and data exfiltration through compromised attestation channels. No other fixes or workarounds have been confirmed by the vendor at this time.

Background: Data exfiltration

Prevent data exfiltration by enforcing least privilege access and monitoring outbound traffic for anomalies. You must restrict who can touch sensitive data and verify where that data travels. Blocking common ports is insufficient because attackers use standard HTTPS channels to hide their activity.

Read the full guide: How to Prevent Data Exfiltration: Stop Silent Data Loss

What to do and how to stay safe: Privasys

• Audit all deployments of Privasys Enclave OS Mini to identify instances running versions prior to wasm-v0.40.0.
• Prioritize the installation of the wasm-v0.40.0 update on all affected systems to close the RA-TLS relay vulnerability.
• Monitor network logs for anomalous attestation requests or repeated quote validations that may indicate active exploitation attempts.
• Review remote attestation policies to ensure relying parties are not accepting quotes without strict session binding verification.

General security guidance from the Circuit Observer newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

What is the severity of CVE-2026-108265?

The National Vulnerability Database rates the severity as Critical with a CVSS score of 9.1.

Which versions of Enclave OS Mini are vulnerable?

All versions of Privasys Enclave OS Mini prior to wasm-v0.40.0 are affected by this vulnerability.

How was the vulnerability fixed?

The issue was fixed in version wasm-v0.40.0 by ensuring the RA-TLS challenge certificate path includes a value bound to the active TLS session.