FindServers Memory Exhaustion in open62541

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-33592
StatePUBLISHED
AssignerENISA
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-02 08:16:39 UTC
Updated2026-07-02 17:39:07 UTC
DescriptionAn 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from a6d3dc9e-0591-4a13-bce7-0f5b31ff6158

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.003880000 probability, percentile 0.307790000 (date 2026-07-04)

Problem Types: CWE-770 | CWE-789 | CWE-770 CWE-770 Allocation of resources without limits or throttling | CWE-789 CWE-789 Memory allocation with excessive size value

VersionSourceTypeScoreSeverityVector
3.1a6d3dc9e-0591-4a13-bce7-0f5b31ff6158Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNACVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Open62541 Project O6 Automation GmbH Open62541 affected 1.4.0 1.4.16 semver Not specified
CNA Open62541 Project O6 Automation GmbH Open62541 affected 1.5.0 1.5.4 semver Not specified
CNA Open62541 Project O6 Automation GmbH Open62541 affected master custom Not specified

References

ReferenceSourceLinkTags
github.com/open62541/open62541/pull/8142 a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 github.com
github.com/open62541/open62541 a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 github.com
github.com/open62541/open62541/pull/8142/changes/d253818d6c5e870e1db0e36... a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Lorenzo Cannella from Fondazione Ugo Bordoni (FUB) (en)

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