What’s Vulnerable › Vulnerabilities
CVE-2026-5466: wc_VerifyEccsiHash missing sanity check
- Severity: high (CVSS 8.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-10 · updated 2026-06-17
- Weakness: CWE-347
Description
wolfSSL's ECCSI signature verifier `wc_VerifyEccsiHash` decodes the `r` and `s` scalars from the signature blob via `mp_read_unsigned_bin` 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 products
- wolfSSL: before 5.9.1 — fixed in 5.9.1
How to fix
Upgrade to a fixed version: wolfSSL 5.9.1. Check the vendor advisory for mitigations.
References
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