Rustls up to 0.23.44 Deframer Deframer::aligned missing encryption

Summaryinfo

A vulnerability identified as problematic has been detected in Rustls up to 0.23.44. Affected by this issue is the function Deframer::aligned of the component Deframer. This manipulation causes missing encryption. This vulnerability appears as CVE-2026-123613. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Rustls up to 0.23.44. It has been declared as problematic. Affected by this vulnerability is the function Deframer::aligned of the component Deframer. The manipulation with an unknown input leads to a missing encryption vulnerability. The CWE definition for the vulnerability is CWE-311. The product does not encrypt sensitive or critical information before storage or transmission. As an impact it is known to affect confidentiality. The summary by CVE is:

Rustls from 0.23.13 before 0.23.45 accepts TLS 1.3 handshake messages at the wrong encryption level when they follow a key-changing message in the same record, because Deframer::aligned does not enforce RFC 8446 record-boundary alignment. A peer or on-path attacker can pack a plaintext EncryptedExtensions with the ServerHello, which rustls accepts unencrypted.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-123613 since 11/06/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1600 according to MITRE ATT&CK.

Upgrading to version 0.23.45 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Rustls

Version

• 0.23.0
• 0.23.1
• 0.23.2
• 0.23.3
• 0.23.4
• 0.23.5
• 0.23.6
• 0.23.7
• 0.23.8
• 0.23.9
• 0.23.10
• 0.23.11
• 0.23.12
• 0.23.13
• 0.23.14
• 0.23.15
• 0.23.16
• 0.23.17
• 0.23.18
• 0.23.19
• 0.23.20
• 0.23.21
• 0.23.22
• 0.23.23
• 0.23.24
• 0.23.25
• 0.23.26
• 0.23.27
• 0.23.28
• 0.23.29
• 0.23.30
• 0.23.31
• 0.23.32
• 0.23.33
• 0.23.34
• 0.23.35
• 0.23.36
• 0.23.37
• 0.23.38
• 0.23.39
• 0.23.40
• 0.23.41
• 0.23.42
• 0.23.43
• 0.23.44

Website

• Product: https://github.com/rustls/rustls/

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