Bug 2496477

Summary:	CVE-2026-33592 open62541: open62541: Remote attacker can cause Denial of Service via FindServers Discovery Service [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Keith Grant <kgrant>
Component:	open62541	Assignee:	Jens Reimann <jreimann>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	rawhide	CC:	jreimann, thofmann
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["4669a34c-eb87-447a-a2fe-bfb206f22aa6"]}
Fixed In Version:	open62541-1.5.6-1.fc44 open62541-1.5.6-1.fc43	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-08-05 00:57:07 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2496405

Description Keith Grant 2026-07-02 12:05:54 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-07-27 13:09:18 UTC

FEDORA-2026-23b21104ef (open62541-1.5.6-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-23b21104ef

Comment 2 Fedora Update System 2026-07-27 13:09:27 UTC

FEDORA-2026-1435f05fde (open62541-1.5.6-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-1435f05fde

Comment 3 Fedora Update System 2026-07-28 01:36:05 UTC

FEDORA-2026-23b21104ef has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-23b21104ef`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-23b21104ef

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-07-28 01:57:44 UTC

FEDORA-2026-1435f05fde has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-1435f05fde`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-1435f05fde

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-08-05 00:57:07 UTC

FEDORA-2026-23b21104ef (open62541-1.5.6-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2026-08-05 01:10:45 UTC

FEDORA-2026-1435f05fde (open62541-1.5.6-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.