CVE-2026-33592
Publication date 3 July 2026
Last updated 4 July 2026
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| open62541 | 26.04 LTS resolute |
Needs evaluation
|
| 25.10 questing |
Needs evaluation
|
|
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release |
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.5 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H