Bug 2500553

Summary:	CVE-2026-15714 libsoup3: libsoup: Out-of-bounds read in soup_multipart_input_stream_read_headers via an oversized multipart boundary string [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": ["7ea88313-b13b-417a-b762-94cb4453c54b"]}
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 01:12:24 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:	2499942

Description Ganesh 2026-07-14 19:45:49 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:

An out-of-bounds (OOB) read flaw was discovered in libsoup's multipart input streaming parser, allowing a remote attacker to trigger a crash or potentially expose sensitive memory contents.

Component / Vulnerable Part:

libsoup -> Multipart handling engine (libsoup/soup-multipart-input-stream.c -> soup_multipart_input_stream_read_headers())

Technical Analysis & Root Cause:

When an application utilizing a SoupSession parses a multipart MIME message response, it invokes soup_multipart_input_stream_read_headers() to extract contextual block structures. A validation vulnerability exists where the logic fails to enforce strict length limits on the incoming boundary string delimiter. If a malicious remote endpoint supplies an exceptionally large multipart boundary string, the internal memory pointer indexing calculations drift past the expected buffer boundaries, triggering an out-of-bounds read operation on the heap or stack layout.

Impact:

A remote, unauthenticated attacker serving a malformed multipart HTTP payload can cause the application process to terminate unexpectedly (Denial of Service) via a segmentation fault or glean layout information from adjacent memory locations.

Comment 1 Aoife Moloney 2026-08-17 15:19:49 UTC

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

Comment 2 Adrian Vovk 2026-09-04 00:28:00 UTC

Proposed upstream fix: https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/546

Comment 3 Fedora Update System 2026-09-05 20:54:51 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 4 Fedora Update System 2026-09-05 20:55:06 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 5 Fedora Update System 2026-09-05 20:55:21 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 6 Fedora Update System 2026-09-06 00:56:59 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 7 Fedora Update System 2026-09-06 01:07:43 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 8 Fedora Update System 2026-09-06 01:26:58 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 9 Fedora Update System 2026-09-08 01:12:24 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 10 Fedora Update System 2026-09-10 01:14:27 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 11 Fedora Update System 2026-09-12 00:18:37 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.