CVE-2026-24785
📋 TL;DR
Clatter versions before 2.2.0 have a protocol compliance vulnerability where post-quantum handshake patterns violate the PSK validity rule, allowing PSK-derived keys to be used without proper randomization. This weakens security guarantees and could lead to catastrophic key reuse. Users of affected post-quantum patterns with PSK are impacted.
💻 Affected Systems
- Clatter (Rust Noise protocol implementation)
📦 What is this software?
Clatter by Jmlepisto
⚠️ Risk & Real-World Impact
Worst Case
Catastrophic key reuse leading to complete compromise of encrypted communications, potentially allowing decryption of past and future sessions
Likely Case
Weakened cryptographic security that could enable sophisticated attackers to compromise specific sessions
If Mitigated
Minimal impact if proper network segmentation and monitoring are in place
🎯 Exploit Status
Exploitation requires sophisticated cryptographic attacks and knowledge of specific handshake patterns in use
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.2.0
Vendor Advisory: https://github.com/jmlepisto/clatter/security/advisories/GHSA-253q-9q78-63x4
Restart Required: Yes
Instructions:
1. Update Cargo.toml to require clatter >=2.2.0
2. Run 'cargo update --package clatter'
3. Rebuild and redeploy applications using Clatter
4. Restart affected services
🔧 Temporary Workarounds
Avoid vulnerable patterns
allStop using affected *_psk0 variants of post-quantum handshake patterns
Modify application code to use non-PSK patterns or different handshake configurations
🧯 If You Can't Patch
- Review and modify all custom handshake patterns to ensure PSK validity rule compliance
- Implement additional network monitoring for unusual cryptographic handshake patterns
🔍 How to Verify
Check if Vulnerable:
Check Cargo.toml or Cargo.lock for clatter version <2.2.0 and verify if application uses affected *_psk0 patternsCheck Version:
grep -A2 -B2 'clatter' Cargo.toml && grep 'clatter' Cargo.lock | head -5Verify Fix Applied:
Confirm clatter version >=2.2.0 in Cargo.lock and verify runtime checks are enabled📡 Detection & Monitoring
Log Indicators:
- Runtime warnings about PSK validity rule violations (if logging enabled in Clatter 2.2.0+)
Network Indicators:
- Unusual handshake patterns matching affected *_psk0 variants
SIEM Query:
Not applicable - cryptographic library issue without standard network signatures