Description
An unauthenticated remote attacker can exhaust server memory via the GetEndpoints Discovery Service in open62541. The endpointUrl field of GetEndpointsRequest is not validated for length. An attacker can declare an arbitrarily large string (up to ~4.09 GB via the UInt32 length field) 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 configurations. The issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master.
References (3)
Core 3
Core References
Product product
https://github.com/open62541/open62541
Patch patch
https://github.com/open62541/open62541/pull/8142
Scores
CVSS v3
7.5
EPSS
0.0038
EPSS Percentile
30.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-770
CWE-789
Status
published
Products (3)
open62541 project / o6 Automation GmbH/open62541
1.4.0 - 1.4.16
open62541 project / o6 Automation GmbH/open62541
1.5.0 - 1.5.4
open62541 project / o6 Automation GmbH/open62541
master
Published
Jul 02, 2026
Tracked Since
Jul 02, 2026