Vulnerability · Published Oct 9, 2026 · Assigned by GitHub_M
CVE-2026-108266Privasys rustls fork: RA-TLS challenge mode did not bind attestation evidence to the TLS session
Critical 9.1
In plain English
A critical-severity security flaw in rustls from Privasys. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:24.04:LTS | rust-rustls | no fix listed | UBUNTU-CVE-2026-108266 |
| Ubuntu:26.04:LTS | rust-rustls | no fix listed | UBUNTU-CVE-2026-108266 |
Affected products (as reported)
Weakness: CWE-346 · Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/Privasys/rustls/security/advisories/GHSA-j6qv-435v-r492 x_refsource_CONFIRM
- https://github.com/Privasys/rustls/commit/ab630583b58fee84260cbbfe2f4a8b45d8bde200 x_refsource_MISC
- https://github.com/Privasys/rustls/releases/tag/privasys-v0.8.1 x_refsource_MISC
- https://privasys.org/blog/binding-attestation-to-the-tls-session x_refsource_MISC