Bug 2454810 (CVE-2026-23455) - CVE-2026-23455 kernel: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()
Summary: CVE-2026-23455 kernel: netfilter: nf_conntrack_h323: check for zero length in...
Keywords:
Status: NEW
Alias: CVE-2026-23455
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-03 16:01 UTC by OSIDB Bzimport
Modified: 2026-07-17 12:52 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-2026:21556 0 None None None 2026-05-28 01:24:00 UTC
Red Hat Product Errata RHSA-2026:21557 0 None None None 2026-05-28 01:19:54 UTC
Red Hat Product Errata RHSA-2026:21706 0 None None None 2026-05-28 08:25:55 UTC
Red Hat Product Errata RHSA-2026:21745 0 None None None 2026-05-28 13:26:24 UTC
Red Hat Product Errata RHSA-2026:25218 0 None None None 2026-06-11 10:53:54 UTC
Red Hat Product Errata RHSA-2026:26462 0 None None None 2026-06-17 01:13:57 UTC
Red Hat Product Errata RHSA-2026:26515 0 None None None 2026-06-17 06:33:35 UTC
Red Hat Product Errata RHSA-2026:27713 0 None None None 2026-06-22 05:01:33 UTC
Red Hat Product Errata RHSA-2026:33899 0 None None None 2026-07-01 00:15:53 UTC
Red Hat Product Errata RHSA-2026:35844 0 None None None 2026-07-06 04:20:44 UTC
Red Hat Product Errata RHSA-2026:35863 0 None None None 2026-07-06 04:51:28 UTC
Red Hat Product Errata RHSA-2026:35896 0 None None None 2026-07-06 14:26:42 UTC
Red Hat Product Errata RHSA-2026:41236 0 None None None 2026-07-17 12:52:25 UTC

Description OSIDB Bzimport 2026-04-03 16:01:58 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()

In DecodeQ931(), the UserUserIE code path reads a 16-bit length from
the packet, then decrements it by 1 to skip the protocol discriminator
byte before passing it to DecodeH323_UserInformation(). If the encoded
length is 0, the decrement wraps to -1, which is then passed as a
large value to the decoder, leading to an out-of-bounds read.

Add a check to ensure len is positive after the decrement.
Comment 1 Jon Moroney 2026-04-03 19:20:01 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026040317-CVE-2026-23455-f045@gregkh/T
Comment 3 errata-xmlrpc 2026-05-28 01:19:53 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:21557 https://access.redhat.com/errata/RHSA-2026:21557
Comment 4 errata-xmlrpc 2026-05-28 01:23:59 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:21556 https://access.redhat.com/errata/RHSA-2026:21556
Comment 5 errata-xmlrpc 2026-05-28 08:25:54 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:21706 https://access.redhat.com/errata/RHSA-2026:21706
Comment 6 errata-xmlrpc 2026-05-28 13:26:23 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:21745 https://access.redhat.com/errata/RHSA-2026:21745
Comment 7 errata-xmlrpc 2026-06-11 10:53:53 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:25218 https://access.redhat.com/errata/RHSA-2026:25218
Comment 8 errata-xmlrpc 2026-06-17 01:13:56 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:26462 https://access.redhat.com/errata/RHSA-2026:26462
Comment 9 errata-xmlrpc 2026-06-17 06:33:35 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:26515 https://access.redhat.com/errata/RHSA-2026:26515
Comment 10 errata-xmlrpc 2026-06-22 05:01:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:27713 https://access.redhat.com/errata/RHSA-2026:27713
Comment 11 errata-xmlrpc 2026-07-01 00:15:52 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-2026:33899 https://access.redhat.com/errata/RHSA-2026:33899
Comment 12 errata-xmlrpc 2026-07-06 04:20:43 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:35844 https://access.redhat.com/errata/RHSA-2026:35844
Comment 13 errata-xmlrpc 2026-07-06 04:51:26 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-2026:35863 https://access.redhat.com/errata/RHSA-2026:35863
Comment 14 errata-xmlrpc 2026-07-06 14:26:41 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-2026:35896 https://access.redhat.com/errata/RHSA-2026:35896
Comment 15 errata-xmlrpc 2026-07-17 12:52:23 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:41236 https://access.redhat.com/errata/RHSA-2026:41236
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