CVE-2026-33592

Summary

An unauthenticated remote attacker can exhaust server memory via the FindServers Discovery Service in open62541. The serverUris field of FindServersRequest is not validated for length or array size. An attacker can declare an arbitrarily large string (up to ~3.9 GB) delivered across intermediate chunks without ever sending the final chunk. The server buffers all chunks in RAM indefinitely until the SecureChannel times out. The attack is pre-session and bypasses all encryption configuration. The issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master.

Affected Software

VendorProductVersion RangeStatus
open62541 project / o6 Automation GmbHopen625411.4.0 <= 1.4.16affected
open62541 project / o6 Automation GmbHopen625411.5.0 <= 1.5.4affected
open62541 project / o6 Automation GmbHopen62541masteraffected

Weaknesses

  • CWE-770: CWE-770 Allocation of resources without limits or throttling
  • CWE-789: CWE-789 Memory allocation with excessive size value

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References