The MultiScalarMult function in the Go library outputs an incorrect point when the receiver is not the identity point. The erroneous result may propagate through cryptographic protocols, causing authentication failures or invalid signatures. This flaw resides in the mathematical core of the library and can invalidate any primitive built upon it. The impact is limited to applications that invoke this rarely used, advanced API.

The vendor FiloSottile provides the library filippo.io/edwards25519. Versions 1.1.0 and earlier are affected. The bug does not affect code that depends on the library indirectly through other packages that never call MultiScalarMult, such as applications that use go-sql-driver/mysql.

The CVSS score of 1.7 and EPSS of less than 1% indicate a very low likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog. The likely attack vector is local code execution via applications that directly invoke MultiScalarMult on a non‑identity receiver. No remote exploitation path is known. Given the low severity and limited exposure, the risk to most users is minimal, but patching remains recommended.