CVE-2025-62514
Severity CVSS v4.0:
Pending analysis
Type:
CWE-327
Use of a Broken or Risky Cryptographic Algorithm
Publication date:
29/01/2026
Last modified:
29/01/2026
Description
Parsec is a cloud-based application for cryptographically secure file sharing. In versions on the 3.x branch prior to 3.6.0, `libparsec_crypto`, a component of the Parsec application, does not check for weak order point of Curve25519 when compiled with its RustCrypto backend. In practice this means an attacker in a man-in-the-middle position would be able to provide weak order points to both parties in the Diffie-Hellman exchange, resulting in a high probability to for both parties to obtain the same shared key (hence leading to a successful SAS code exchange, misleading both parties into thinking no MITM has occurred) which is also known by the attacker. Note only Parsec web is impacted (as Parsec desktop uses `libparsec_crypto` with the libsodium backend). Version 3.6.0 of Parsec patches the issue.
Impact
Base Score 3.x
8.30
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://github.com/Scille/parsec-cloud/blob/e7c5cdbc4234f606ccf3ab2be7e9edc22db16feb/libparsec/crates/crypto/src/rustcrypto/private.rs#L136-L138
- https://github.com/Scille/parsec-cloud/commit/197bb6387b49fec872b5e4a04dcdb82b3d2995b2
- https://github.com/Scille/parsec-cloud/security/advisories/GHSA-hrc9-gm58-pgj9
- https://github.com/dalek-cryptography/curve25519-dalek/blob/8c53a8f10b146a2fd65069437e3576e49b390e7a/curve25519-dalek/src/montgomery.rs#L132-L146
- https://github.com/dalek-cryptography/curve25519-dalek/blob/8c53a8f10b146a2fd65069437e3576e49b390e7a/x25519-dalek/src/x25519.rs#L364-L366



