CVE-2026-123612
rustls 0.23.44 and 0.23.45 ECH Rejection Application Data Disclosure
CVSS Score
2.3
EPSS Score
0.0%
EPSS Percentile
0th
rustls 0.23.44 and 0.23.45 contain an information disclosure vulnerability that sends application data buffered before the handshake completes to the client-facing server when Encrypted Client Hello is rejected. Because start_traffic() queues plaintext from ClientConnection::writer() before sending the ech_required alert, the authenticated public_name server receives data intended for the inner server.
| CWE | CWE-696 |
| Vendor | rustls |
| Product | rustls |
| Published | Nov 8, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
rustls / rustls
0.23.44 < 0.23.46