jmlepisto clatter up to 2.1.x risky encryption

Summaryinfo

A vulnerability has been found in jmlepisto clatter up to 2.1.x and classified as problematic. Affected by this issue is some unknown functionality. The manipulation leads to risky encryption. This vulnerability is uniquely identified as CVE-2026-24785. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in jmlepisto clatter up to 2.1.x and classified as critical. This issue affects an unknown part. The manipulation with an unknown input leads to a risky encryption vulnerability. Using CWE to declare the problem leads to CWE-327. The product uses a broken or risky cryptographic algorithm or protocol. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Clatter is a no_std compatible, pure Rust implementation of the Noise protocol framework with post-quantum support. Versiosn prior to2.2.0 have a protocol compliance vulnerability. The library allowed post-quantum handshake patterns that violated the PSK validity rule (Noise Protocol Framework Section 9.3). This could allow PSK-derived keys to be used for encryption without proper randomization by self-chosen ephemeral randomness, weakening security guarantees and potentially allowing catastrophic key reuse. Affected default patterns include `noise_pqkk_psk0`, `noise_pqkn_psk0`, `noise_pqnk_psk0`, `noise_pqnn_psk0``, and some hybrid variants. Users of these patterns may have been using handshakes that do not meet the intended security properties. The issue is fully patched and released in Clatter v2.2.0. The fixed version includes runtime checks to detect offending handshake patterns. As a workaround, avoid using offending `*_psk0` variants of post-quantum patterns. Review custom handshake patterns carefully.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-24785 since 01/26/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1600 for this issue.

Upgrading to version 2.2.0 eliminates this vulnerability. Applying the patch b65ae6e9b8019bed5407771e21f89ddff17c5a71 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CNNVD (CNNVD-202601-4624). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• jmlepisto

Name

• clatter

Version

• 2.0
• 2.1

License

• open-source

Website

• Product: https://github.com/jmlepisto/clatter/

CPE 2.3info

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CPE 2.2info

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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