Quick answers
- Is CVE-2026-16516 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-16516 being exploited in the wild.
- How severe is CVE-2026-16516?
- Informational severity, published 7 October 2026.
- Which products and versions are affected?
- wolfSSL wolfSSH.
- Is there a fix for CVE-2026-16516?
- A patch was published on 2026-06-15: Fix committed before disclosure date; likely version not yet released at disclosure Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-16516 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-16516?
- Check whether you run Wolfssl wolfSSH. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a cryptographic validation bypass (CWE-345) in ParseECCPubKey() in src/internal.c. During KEXDH_REPLY processing, the function derives the ECDSA curve from the key blob's algorithm string without validating it against the negotiated ssh->handshake->pubKeyId, and skips reading the RFC 5656 curve identifier instead of comparing it. An active MitM attacker can send a host key with a substituted curve (e.g., nistp384 instead of negotiated nistp256), which wolfSSH accepts. Exploitation requires both network-level MitM capability and a lax public key validation callback; the attacker controls the substituted key's private key so signatures still verify.
Affected products
- wolfSSL wolfSSH
Timeline
- 2026-10-07: disclosed
- 2026-06-15: patched: Fix committed before disclosure date; likely version not yet released at disclosure