CVE-2026-108266: Privasys rustls fork: RA-TLS challenge mode did not bind attestation evidence to the TLS session
Privasys rustls is a maintained fork of the rustls TLS library that adds RA-TLS challenge and channel-binding support. Prior to privasys-v0.8.1, the fork emitted RA-TLS challenge certificates whose quote ReportData was bound to the certificate public key and client nonce but not 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 privasys-v0.8.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Privasys rustlsto a version that resolves this vulnerability.Fixed in v0.8.1
Event History
Frequently Asked Questions
What must an attacker obtain to exploit this issue?
The attacker must obtain an enclave TLS private key. With that key, they can relay a genuine attestation quote to a different connection and impersonate the attested enclave to a relying party.
Which deployments are affected?
Deployments using Privasys rustls RA-TLS challenge certificates are affected before privasys-v0.8.1. The issue concerns challenge-mode certificates whose attestation evidence was not bound to the active TLS session.
What is the available remediation?
Upgrade to privasys-v0.8.1, which fixes the missing binding between the quote ReportData and the active TLS session.