CVE-2026-5187

Summary

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.

Affected Software

VendorProductVersion RangeStatus
wolfSSLwolfSSL0 <= 5.9.0affected

Weaknesses

  • CWE-122: CWE-122: Heap-based Buffer Overflow
  • CWE-787: CWE-787: Out-of-bounds Write

Workarounds

Do not enable WC_ASN_UNKNOWN_EXT_CB or do not register an unknown extension callback if not required. This mitigates the network-reachable variant (Bug 2) but does not address Bug 1.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References