CVE-2026-5466 | BDVDB-2026-326227 Detail

wolfSSLwolfSSL

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.

Impact#

Per CVSS v4.0: confidentiality impact high, integrity impact high, availability impact none. Attack vector: adjacent.

Weaknesses#

CWE-347 Improper verification of cryptographic signature

References#

https://github.com/wolfssl/wolfssl/pull/10102

Exploit#

No public exploit known

History#

Version 12026-04-10Record published in the CVE List.
Version 22026-04-22Most recent update recorded in the CVE List.

Published

Published: 2026-04-10
Last modified: 2026-04-22

Vendor information

Vendor: wolfSSL
Product: wolfSSL

All wolfSSL vulnerabilities

Score

7.6 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 9.5.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 5.9.1
Fixed
5.9.1

Scoring System

CVSS v4.0

7.6 High

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

Metric breakdown
Attack Vector	Adjacent
Attack Complexity	Low
Attack Requirements	Present
Privileges Required	None
User Interaction	None
Vulnerable System Confidentiality	High
Vulnerable System Integrity	High
Vulnerable System Availability	None
Subsequent System Confidentiality	None
Subsequent System Integrity	None
Subsequent System Availability	None

CVSS v3.1

Not available

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).