Bug 2467064 (CVE-2026-43190) - CVE-2026-43190 kernel: netfilter: xt_tcpmss: check remaining length before reading optlen
Summary: CVE-2026-43190 kernel: netfilter: xt_tcpmss: check remaining length before re...
Keywords:
Status: NEW
Alias: CVE-2026-43190
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-06 13:02 UTC by OSIDB Bzimport
Modified: 2026-06-22 04:26 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 01:24:09 UTC
Red Hat Product Errata RHSA-2026:21557 0 None None None 2026-05-28 01:20:05 UTC
Red Hat Product Errata RHSA-2026:21706 0 None None None 2026-05-28 08:26:08 UTC
Red Hat Product Errata RHSA-2026:21745 0 None None None 2026-05-28 13:26:34 UTC
Red Hat Product Errata RHSA-2026:25028 0 None None None 2026-06-10 09:49:32 UTC
Red Hat Product Errata RHSA-2026:25218 0 None None None 2026-06-11 10:53:57 UTC
Red Hat Product Errata RHSA-2026:25533 0 None None None 2026-06-12 19:51:49 UTC
Red Hat Product Errata RHSA-2026:26462 0 None None None 2026-06-17 01:14:01 UTC
Red Hat Product Errata RHSA-2026:26515 0 None None None 2026-06-17 06:33:38 UTC
Red Hat Product Errata RHSA-2026:26535 0 None None None 2026-06-17 09:18:48 UTC
Red Hat Product Errata RHSA-2026:26563 0 None None None 2026-06-17 11:58:36 UTC
Red Hat Product Errata RHSA-2026:27729 0 None None None 2026-06-22 04:26:59 UTC

Description OSIDB Bzimport 2026-05-06 13:02:19 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: xt_tcpmss: check remaining length before reading optlen

Quoting reporter:
  In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads
 op[i+1] directly without validating the remaining option length.

  If the last byte of the option field is not EOL/NOP (0/1), the code attempts
  to index op[i+1]. In the case where i + 1 == optlen, this causes an
  out-of-bounds read, accessing memory past the optlen boundary
  (either reading beyond the stack buffer _opt or the
  following payload).
Comment 1 Keith Grant 2026-05-06 20:41:36 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050642-CVE-2026-43190-f1c9@gregkh/T
Comment 3 errata-xmlrpc 2026-05-28 01:20:04 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 01:24:08 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 08:26:07 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 13:26:32 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 2026-06-10 09:49:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:25028 https://access.redhat.com/errata/RHSA-2026:25028
Comment 8 errata-xmlrpc 2026-06-11 10:53:56 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 9 errata-xmlrpc 2026-06-12 19:51:48 UTC 
This issue has been addressed in the following products:

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

Via RHSA-2026:25533 https://access.redhat.com/errata/RHSA-2026:25533
Comment 10 errata-xmlrpc 2026-06-17 01:14:00 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 11 errata-xmlrpc 2026-06-17 06:33:37 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 12 errata-xmlrpc 2026-06-17 09:18:48 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-2026:26535 https://access.redhat.com/errata/RHSA-2026:26535
Comment 13 errata-xmlrpc 2026-06-17 11:58:35 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-2026:26563 https://access.redhat.com/errata/RHSA-2026:26563
Comment 14 errata-xmlrpc 2026-06-22 04:26:58 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:27729 https://access.redhat.com/errata/RHSA-2026:27729
Note You need to log in before you can comment on or make changes to this bug.