CVE-2026-26958
📋 TL;DR
This vulnerability in the filippo.io/edwards25519 Go library causes the MultiScalarMult function to produce invalid cryptographic results or undefined behavior when called on non-identity points. It affects users who directly call this advanced API in their applications, potentially leading to cryptographic failures. Users who only use the library indirectly through dependencies like github.com/go-sql-driver/mysql are not affected.
💻 Affected Systems
- filippo.io/edwards25519 Go library
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Cryptographic operations using MultiScalarMult produce invalid results, potentially breaking authentication, signature verification, or key agreement protocols that rely on correct elliptic curve computations.
Likely Case
Applications using MultiScalarMult API incorrectly produce invalid cryptographic outputs, causing functional failures in specific cryptographic operations.
If Mitigated
Limited impact since MultiScalarMult is a rarely used advanced API, and most users won't be affected if they don't call this specific function.
🎯 Exploit Status
Exploitation requires specific knowledge of the MultiScalarMult API usage and ability to trigger calls with non-identity points.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.1.1
Vendor Advisory: https://github.com/FiloSottile/edwards25519/security/advisories/GHSA-fw7p-63qq-7hpr
Restart Required: Yes
Instructions:
1. Update Go module dependency to filippo.io/edwards25519 v1.1.1
2. Run 'go mod tidy' to update dependencies
3. Rebuild and redeploy affected applications
4. Restart services using the updated library
🔧 Temporary Workarounds
Avoid MultiScalarMult usage
allEnsure MultiScalarMult is only called with identity points as receivers
// Code review to ensure all MultiScalarMult calls use identity points
// Example: var p edwards25519.Point
// p.MultiScalarMult(...) // Only call if p is identity
🧯 If You Can't Patch
- Audit codebase for MultiScalarMult usage and ensure all calls use identity points as receivers
- Implement input validation to prevent MultiScalarMult calls with non-identity points
🔍 How to Verify
Check if Vulnerable:
Check go.mod or go.sum for filippo.io/edwards25519 version <1.1.1Check Version:
grep 'filippo.io/edwards25519' go.modVerify Fix Applied:
Verify go.mod contains filippo.io/edwards25519 v1.1.1 or later📡 Detection & Monitoring
Log Indicators:
- Application errors related to cryptographic operations
- Invalid signature or authentication failures
Network Indicators:
- Failed cryptographic handshakes in protocols using edwards25519
SIEM Query:
Application logs containing 'MultiScalarMult' or cryptographic operation failures