Bug 2540479 (CVE-2026-97417)

Summary: CVE-2026-97417 kernel: netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's netfilter connection tracking subsystem. The TCP option processing mechanism improperly assumes memory alignment when reading packet headers. A remote attacker could exploit this vulnerability by sending crafted TCP packets with misaligned SACK options through a system running conntrack (e.g., Linux firewall/NAT using iptables/nftables), causing a memory access fault that leads to a kernel panic and Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-24 16:59:06 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()

The timestamp-only fast path dereferences the option stream as
*(__be32 *)ptr, which assumes 4-byte alignment that the TCP option
stream does not guarantee. Use get_unaligned_be32() instead, which
reads the value safely and already returns host byte order, so the
htonl() on the comparison constant can be dropped.

This matches the existing get_unaligned_be32() use later in the same
function.
Comment 1 Mauro Matteo Cascella 2026-09-25 07:37:07 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97417.mbox
Comment 5 Jon Orris 2026-10-05 10:49:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:75746 https://access.redhat.com/errata/RHSA-2026:75746
Comment 6 Jon Orris 2026-10-05 11:24:11 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:75747 https://access.redhat.com/errata/RHSA-2026:75747
Comment 7 Jon Orris 2026-10-07 20:28:47 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:76738 https://access.redhat.com/errata/RHSA-2026:76738
Comment 8 Jon Orris 2026-10-08 09:50:34 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:76739 https://access.redhat.com/errata/RHSA-2026:76739