CVE-2026-5466
High
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.
SeverityHigh
CVSS8.1
Exploit probability—
ProductWolfssl
PublishedApr 10, 2026
First seenApr 10, 2026
Weakness typeCWE-347CWE-347
How to fix
Update
- wolfssl wolfssl5.9.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| wolfssl wolfssl | v < 5.9.1 | 5.9.1 |
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