Bug 2543296 (CVE-2026-102560) - CVE-2026-102560 libsoup: libsoup: Heap buffer overflow during outgoing permessage-deflate buffer growth
Summary: CVE-2026-102560 libsoup: libsoup: Heap buffer overflow during outgoing permes...
Keywords:
Status: NEW
Alias: CVE-2026-102560
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-29 16:50 UTC by OSIDB Bzimport
Modified: 2026-11-11 11:51 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:83384 0 None None None 2026-10-15 02:58:58 UTC
Red Hat Product Errata RHSA-2026:83618 0 None None None 2026-10-15 15:54:04 UTC
Red Hat Product Errata RHSA-2026:93445 0 None None None 2026-11-02 02:28:35 UTC
Red Hat Product Errata RHSA-2026:93446 0 None None None 2026-11-02 03:33:58 UTC
Red Hat Product Errata RHSA-2026:93447 0 None None None 2026-11-02 02:36:03 UTC
Red Hat Product Errata RHSA-2026:93583 0 None None None 2026-11-02 08:58:22 UTC
Red Hat Product Errata RHSA-2026:98453 0 None None None 2026-11-11 11:51:03 UTC
Red Hat Product Errata RHSA-2026:98560 0 None None None 2026-11-11 11:19:31 UTC

Description OSIDB Bzimport 2026-09-29 16:50:24 UTC 
A heap buffer overflow was found in libsoup's WebSocket permessage-deflate outgoing path.

soup_websocket_extension_deflate_process_outgoing_message() stored deflateBound()'s uLong result in a guint and grew a GByteArray by that amount. For payloads approaching 4 GiB, the bound exceeds G_MAXUINT; truncation allowed buffer->len + max_length to wrap on later growth, and zlib wrote through next_out past the allocation.

Fixed by refusing payloads whose compressed bound cannot fit in a GByteArray and by checking each incremental growth (commit dbd0417e, libsoup 3.7.3).

References:
https://gitlab.gnome.org/GNOME/libsoup/-/work_items/554 (Bug 8)
https://gitlab.gnome.org/GNOME/libsoup/-/commit/dbd0417e
Comment 1 Jon Orris 2026-10-15 02:58:57 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:83384 https://access.redhat.com/errata/RHSA-2026:83384
Comment 2 Jon Orris 2026-10-15 15:54:03 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:83618 https://access.redhat.com/errata/RHSA-2026:83618
Comment 3 Jon Orris 2026-11-02 02:28:34 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:93445 https://access.redhat.com/errata/RHSA-2026:93445
Comment 4 Jon Orris 2026-11-02 02:36:02 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:93447 https://access.redhat.com/errata/RHSA-2026:93447
Comment 5 Jon Orris 2026-11-02 03:33:57 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:93446 https://access.redhat.com/errata/RHSA-2026:93446
Comment 6 Jon Orris 2026-11-02 08:58:21 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:93583 https://access.redhat.com/errata/RHSA-2026:93583
Comment 7 errata-xmlrpc 2026-11-11 11:19:29 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:98560 https://access.redhat.com/errata/RHSA-2026:98560
Comment 8 errata-xmlrpc 2026-11-11 11:51:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:98453 https://access.redhat.com/errata/RHSA-2026:98453
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