Bug 2543285 (CVE-2026-102559) - CVE-2026-102559 libsoup: libsoup: Heap buffer overflow during WebSocket client-frame masking
Summary: CVE-2026-102559 libsoup: libsoup: Heap buffer overflow during WebSocket clien...
Keywords:
Status: NEW
Alias: CVE-2026-102559
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 16:39 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 RHBA-2026:87453 0 None None None 2026-10-22 02:30:17 UTC
Red Hat Product Errata RHSA-2026:83384 0 None None None 2026-10-15 02:58:57 UTC
Red Hat Product Errata RHSA-2026:83618 0 None None None 2026-10-15 15:54:04 UTC
Red Hat Product Errata RHSA-2026:84586 0 None None None 2026-10-19 04:01:59 UTC
Red Hat Product Errata RHSA-2026:92347 0 None None None 2026-10-29 11:08:33 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-2026:93465 0 None None None 2026-11-02 03:31:04 UTC
Red Hat Product Errata RHSA-2026:93466 0 None None None 2026-11-02 03:33:51 UTC
Red Hat Product Errata RHSA-2026:93583 0 None None None 2026-11-02 08:58:20 UTC
Red Hat Product Errata RHSA-2026:93716 0 None None None 2026-11-02 12:47:03 UTC
Red Hat Product Errata RHSA-2026:98453 0 None None None 2026-11-11 11:51:00 UTC
Red Hat Product Errata RHSA-2026:98560 0 None None None 2026-11-11 11:19:28 UTC

Description OSIDB Bzimport 2026-09-29 16:39:50 UTC 
A heap buffer overflow was found in libsoup's client-side WebSocket frame construction / masking path.

Outgoing frames are built in a GByteArray. For a send payload larger than the array can represent (at/above ~2^31), g_byte_array_sized_new() / append truncated the length while xor_with_mask() still iterated the full attacker-/caller-controlled length, writing past the small allocation during masking.

Fixed by rejecting outgoing payloads above MAX_OUTGOING_PAYLOAD_SIZE both before and after extensions process the payload (commit d7f074f8, libsoup 3.7.3).

References:
https://gitlab.gnome.org/GNOME/libsoup/-/work_items/554 (Bug 7)
https://gitlab.gnome.org/GNOME/libsoup/-/commit/d7f074f8
Comment 1 Jon Orris 2026-10-15 02:58:56 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 2026-10-19 04:01:59 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:84586 https://access.redhat.com/errata/RHSA-2026:84586
Comment 4 Jon Orris 2026-10-29 11:08:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:92347 https://access.redhat.com/errata/RHSA-2026:92347
Comment 5 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 6 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 7 Jon Orris 2026-11-02 03:31:03 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:93465 https://access.redhat.com/errata/RHSA-2026:93465
Comment 8 Jon Orris 2026-11-02 03:33:50 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:93466 https://access.redhat.com/errata/RHSA-2026:93466
Comment 9 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 10 Jon Orris 2026-11-02 08:58:20 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 11 Jon Orris 2026-11-02 12:47:02 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

Via RHSA-2026:93716 https://access.redhat.com/errata/RHSA-2026:93716
Comment 12 errata-xmlrpc 2026-11-11 11:19:26 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 13 errata-xmlrpc 2026-11-11 11:50:59 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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