CVE-2026-5188
highAn integer underflow issue exists in wolfSSL when parsing the Subject Alternative Name (SAN) extension of X.509 certificates.
Vendor / product: Wolfssl — wolfssl
An integer underflow issue exists in wolfSSL when parsing the Subject Alternative Name (SAN) extension of X.509 certificates. A malformed certificate can specify an entry length larger than the enclosing sequence, causing the internal length counter to wrap during parsing. This results in incorrect handling of certificate data. The issue is limited to configurations using the original ASN.1 parsing implementation which is off by default.
CVSS
8.1
8.1 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-04-10 04:17
Modified: 2026-11-11 23:10
NVD status: Analyzed
Last synced 3 hours ago
Verified against the source API 2026-11-11 23:12 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
wolfssl / wolfssl <5.9.1
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Patch / mitigation: https://github.com/wolfSSL/wolfssl/pull/10024
References
- https://github.com/wolfSSL/wolfssl/pull/10024 facts@wolfssl.com
Data sources
NVD CVE API 2.0 — fetched 2026-11-11 23:12 UTC · record ↗