CVE-2026-33592: high-severity vulnerability in open62541
FindServers Memory Exhaustion in open62541
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
open62541 project / o6 Automation GmbH · open62541Related CVEs — open62541
In the same product, most dangerous first.