CVE-2026-5187

CRITICAL

Heap Out-of-Bounds Write in DecodeObjectId() in wolfSSL

Title source: cna
STIX 2.1

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.

References (1)

Core 1
Core References
wolfSSL GitHub Repository
https://github.com/wolfSSL/wolfssl

Scores

CVSS v3 9.8
EPSS 0.0028
EPSS Percentile 19.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-122 CWE-787
Status published
Products (2)
wolfSSL/wolfSSL < 5.9.0
wolfssl/wolfssl < 5.9.0
Published Apr 09, 2026
Tracked Since Apr 10, 2026