CVE-2026-5188Integer underflow in X.509 SAN parsing in wolfSSL
Updated under an hour ago ()
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It affects wolfSSL. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 2.3 LOW (v4.0, CNA)CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-191
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- wolfSSL
- NVD analysis
- Analyzed
- Record last updated
- Apr 10, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.