Vulnerability · Published Apr 10, 2026 · Assigned by wolfSSL
CVE-2026-5466wc_VerifyEccsiHash missing sanity check
High 7.6
In plain English
A high-severity security flaw in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)7.6High
Exploit odds (30 days)0.2%top 91.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-5466 |
| Alpine:v3.24 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-5466 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2026-5466 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2026-5466 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5466 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5466 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-5466 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-5466 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-5466 |
Affected products (as reported)
Weakness: CWE-347 · Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N