Bug 2500545

Summary:	CVE-2026-15711 libsoup3: libsoup: WebSocket remote denial of service via oversized control frame protocol violation [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Ganesh <gnaik>
Component:	libsoup3	Assignee:	Adrian Vovk <avovk>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	45	CC:	avovk, gnome-sig, gwync, mcrha
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["92105fae-a4eb-42af-8c14-cd9455b3cbd9"]}
Fixed In Version:	libsoup3-3.6.6-10.fc44 libsoup3-3.6.6-5.fc43 libsoup3-3.7.2-2.fc45	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-09-08 01:12:18 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:	2499924

Description Ganesh 2026-07-14 19:38:25 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.

**Vulnerability Reference:**

A flaw in libsoup's WebSocket implementation allows a remote attacker to trigger a denial of service (DoS) by exploiting a protocol validation failure.

**Component / Vulnerable Part:**

`libsoup` -> `libsoup/websocket/soup-websocket-connection.c` (Control frame parser)

**Technical Analysis & Root Cause:**

Per RFC 6455 §5.5, WebSocket control frames (PING, PONG, CLOSE) must not exceed a payload length of 125 bytes and cannot be fragmented. libsoup's frame parsing logic fails to immediately reject non-compliant control frames exceeding this limit. When an oversized control frame is received, the unexpected state disrupts the state machine or triggers an unhandled execution error, forcing the library to abruptly crash.

**Impact:**

A remote, unauthenticated attacker (client or server) can send a single malformed, oversized control frame to instantly terminate the connection wrapper, resulting in a remote denial of service for any application using libsoup WebSockets.

Comment 1 Aoife Moloney 2026-08-17 15:19:39 UTC

This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.

Comment 2 Fedora Update System 2026-09-05 20:54:44 UTC

FEDORA-2026-3f60ccf61f (libsoup3-3.6.6-10.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3f60ccf61f

Comment 3 Fedora Update System 2026-09-05 20:55:00 UTC

FEDORA-2026-ce24b84bb1 (libsoup3-3.7.2-2.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-ce24b84bb1

Comment 4 Fedora Update System 2026-09-05 20:55:15 UTC

FEDORA-2026-fce2f41203 (libsoup3-3.6.6-5.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-fce2f41203

Comment 5 Fedora Update System 2026-09-06 00:56:55 UTC

FEDORA-2026-3f60ccf61f 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-2026-3f60ccf61f`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-3f60ccf61f

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

Comment 6 Fedora Update System 2026-09-06 01:07:38 UTC

FEDORA-2026-ce24b84bb1 has been pushed to the Fedora 45 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-ce24b84bb1`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-ce24b84bb1

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

Comment 7 Fedora Update System 2026-09-06 01:26:53 UTC

FEDORA-2026-fce2f41203 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-fce2f41203`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-fce2f41203

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

Comment 8 Fedora Update System 2026-09-08 01:12:18 UTC

FEDORA-2026-3f60ccf61f (libsoup3-3.6.6-10.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 9 Fedora Update System 2026-09-10 01:14:23 UTC

FEDORA-2026-fce2f41203 (libsoup3-3.6.6-5.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 10 Fedora Update System 2026-09-12 00:18:31 UTC

FEDORA-2026-ce24b84bb1 (libsoup3-3.7.2-2.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.