Vulnerability Description
Two potential heap out-of-bounds write locations existed in DecodeObjectId() in wolfcrypt/src/asn.c. First, a bounds check only validates one available slot before writing two OID arc values (out[0] and out[1]), enabling a 2-byte out-of-bounds write when outSz equals 1. Second, multiple callers pass sizeof(decOid) (64 bytes on 64-bit platforms) instead of the element count MAX_OID_SZ (32), causing the function to accept crafted OIDs with 33 or more arcs that write past the end of the allocated buffer.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Wolfssl | Wolfssl | <= 5.9.0 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-5187?
CVE-2026-5187 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Two potential heap out-of-bounds write locations existed in DecodeObjectId() in wolfcrypt/src/asn.c. First, a bounds check only validates one available slot before writing two OID arc values (out[0] a...
How severe is CVE-2026-5187?
CVE-2026-5187 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-5187?
Check the references section above for vendor advisories and patch information. Affected products include: Wolfssl Wolfssl.