CVE-2026-24785
Clatter has a PSK Validity Rule Violation issue
Impact
### Impact 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. ### Patches The issue is fully patched and released in Clatter v2.2.0. The fixed version includes runtime checks to detect offending handshake patterns. ### Workarounds Avoid using offending `*_psk0` variants of post-quantum patterns. Review custom handshake patterns carefully. ### Resources * [PSK validity rule](https://noiseprotocol.org/noise.html#validity-rule)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | clatter | < 2.2.0 | 2.2.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Jmlepisto | Clatter | before 2.2.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/jmlepisto/clatter/commit/b65ae6e9b8019bed5407771e21f89ddff17c5a71
- https://github.com/jmlepisto/clatter/security/advisories/GHSA-253q-9q78-63x4
- https://noiseprotocol.org/noise.html#validity-rule
- https://github.com/advisories/GHSA-253q-9q78-63x4
- https://nvd.nist.gov/vuln/detail/CVE-2026-24785