CVE-2026-5466: wc_VerifyEccsiHash missing sanity check
wolfSSL's ECCSI signature verifier wcVerifyEccsiHash decodes the r and s scalars from the signature blob via mpreadunsignedbin with no check that they lie in [1, q-1]. A crafted forged signature could verify against any message for any identity, using only publicly-known constants.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-5466?
CVE-2026-5466 is considered a high-severity vulnerability due to the potential for forged signatures associated with critical cryptographic operations.
How do I fix CVE-2026-5466?
To fix CVE-2026-5466, update your wolfSSL library to the latest version where the sanity check has been implemented in the wc_VerifyEccsiHash function.
Who is affected by CVE-2026-5466?
CVE-2026-5466 affects users of the wolfSSL library that utilize the ECCSI signature verification function without additional safeguards.
What type of attack does CVE-2026-5466 enable?
CVE-2026-5466 enables an attacker to forge signatures that could incorrectly verify against any message for any identity.
Is there a workaround for CVE-2026-5466?
Currently, the best approach for CVE-2026-5466 is to apply the recommended update from wolfSSL, as there are no effective workarounds available.