PT-2026-54729 · Open62541 Project / O6 Automation Gmbh · Open62541

Lorenzo Cannella · Published 2026-07-02 · Updated 2026-07-02 · CVE-2026-33592

Mitre

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Fix

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

CWE-789

Related Identifiers

CVE-2026-33592

Affected Products

Open62541

References · 4

• https://github.com/open62541/open62541/pull/8142 · Patch
• https://github.com/open62541/open62541/pull/8142/changes/d253818d6c5e870e1db0e360b18138c8bdc809ae · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-33592 · Security Note
• https://github.com/open62541/open62541 · Note