Description
A flaw was found in libsoup. When the permessage-deflate WebSocket extension compresses a very large outgoing message, truncated size calculations used for GByteArray growth could wrap, causing zlib to write past the allocated buffer and resulting in a heap buffer overflow.
Published: 2026-09-29
Score: 8.6 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Workaround

To mitigate this disable the permessage-deflate WebSocket extension if it is not required, and cap outgoing message sizes.

Tracking

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8975-1 libsoup vulnerabilities
History

Wed, 04 Nov 2026 22:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:8
cpe:/o:redhat:rhel_els:6
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els

Mon, 02 Nov 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Redhat enterprise Linux Eus
CPEs cpe:/o:redhat:enterprise_linux_eus:10.0
Vendors & Products Redhat enterprise Linux Eus
References

Mon, 02 Nov 2026 05:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.6::appstream
Vendors & Products Redhat rhel Eus
References

Mon, 02 Nov 2026 02:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel E4s
CPEs cpe:/a:redhat:rhel_e4s:9.2::appstream
cpe:/a:redhat:rhel_e4s:9.4::appstream
Vendors & Products Redhat rhel E4s
References

Fri, 16 Oct 2026 14:15:00 +0000

Type Values Removed Values Added
First Time appeared Gnome
Gnome libsoup
CPEs cpe:2.3:a:gnome:libsoup:*:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
Vendors & Products Gnome
Gnome libsoup

Thu, 15 Oct 2026 17:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:10.2
References

Thu, 15 Oct 2026 05:30:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:9 cpe:/a:redhat:enterprise_linux:9::appstream
References

Wed, 30 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Libsoup
Libsoup libsoup
Vendors & Products Libsoup
Libsoup libsoup

Tue, 29 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 29 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in libsoup. When the permessage-deflate WebSocket extension compresses a very large outgoing message, truncated size calculations used for GByteArray growth could wrap, causing zlib to write past the allocated buffer and resulting in a heap buffer overflow.
Title Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growth
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-125
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'}


Subscriptions

Gnome Libsoup
Libsoup Libsoup
Redhat Enterprise Linux Enterprise Linux Eus Rhel E4s Rhel Els Rhel Eus
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-11-04T21:44:36.664Z

Reserved: 2026-09-29T13:19:27.962Z

Link: CVE-2026-102560

cve-icon Vulnrichment

Updated: 2026-09-29T19:51:48.856Z

cve-icon NVD

Status : Modified

Published: 2026-09-29T18:17:08.750

Modified: 2026-11-04T22:17:44.253

Link: CVE-2026-102560

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-30T20:40:30Z

Weaknesses