CVE-2026-33592

EUVD-2026-41256

02.07.2026, 08:16

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.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: 31.42%

Debian Releases

Debian Product

Codename

open62541

forky	vulnerable
sid	vulnerable
trixie	no-dsa

Ubuntu Releases

Ubuntu Product

Codename

open62541

jammy	dne
noble	dne
questing	ignored
resolute	needs-triage

Common Weakness Enumeration

CWE-770 - Allocation of Resources Without Limits or Throttling
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

References

https://github.com/open62541/open62541

https://github.com/open62541/open62541/pull/8142

https://github.com/open62541/open62541/pull/8142/changes/d253818d6c5e870e1db0e360b18138c8bdc809ae