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Linux Kernel EUVDEUVD-2026-59152

| CVE-2026-72253 HIGH
2026-08-15 416baaa9-dc9f-4396-8d5f-8c081fb06d67 GHSA-7j9w-2xg9-r3v4
7.5
CVSS 3.1 · Vendor: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Severity by source

Vendor (416baaa9-dc9f-4396-8d5f-8c081fb06d67) PRIMARY
7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vuln.today AI
5.9 MEDIUM

AC:H reflects the non-default sip_external_media=1 requirement combined with the OVS/tc ingress topology prerequisite; no confidentiality or integrity impact applies.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SUSE
5.9 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Red Hat
7.0 MEDIUM
qualitative

Primary rating from Vendor (416baaa9-dc9f-4396-8d5f-8c081fb06d67).

CVSS VectorVendor: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

5
Analysis Generated
Aug 17, 2026 - 07:59 vuln.today
CVSS changed
Aug 17, 2026 - 06:22 NVD
7.5 (HIGH)
Patch available
Aug 15, 2026 - 07:20 EUVD
CVE Published
Aug 15, 2026 - 06:21 cve.org
HIGH 7.5
CVE Published
Aug 15, 2026 - 06:21 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_sip: validate skb_dst() before accessing it

tc ingress and openvswitch do not guarantee routing information to be available. These subsystems use the conntrack helper infrastructure, and the SIP helper relies on the skb_dst() to be present if sip_external_media is set to 1 (which is disabled by default as a module parameter).

This effectively disables the sip_external_media toggle for these subsystems without resulting in a crash.

AnalysisAI

Null pointer dereference in the Linux kernel's netfilter SIP connection tracking helper (nf_conntrack_sip) can crash the kernel when the non-default sip_external_media=1 module parameter is active and SIP traffic traverses tc ingress or OpenVSwitch paths. Successful exploitation causes a complete availability loss (kernel panic/crash), satisfying the CVSS A:H rating. No public exploit code has been identified and EPSS sits at the 11th percentile, indicating low observed exploitation activity despite the high base score.

Technical ContextAI

The Linux kernel's netfilter subsystem includes nf_conntrack_sip, a connection tracking helper for SIP (Session Initiation Protocol) that inspects and rewrites SIP signalling to handle NAT traversal. The helper optionally tracks external media endpoints when the sip_external_media module parameter is set to 1. In this mode, the code accesses the socket buffer's destination routing entry via skb_dst(), assuming it is always populated. However, tc (traffic control) ingress hooks and OpenVSwitch (OVS) do not guarantee that routing information is attached to the skb - a valid operating condition for those subsystems. This missing pre-condition validation constitutes a CWE-476 (NULL Pointer Dereference)-class flaw: when a SIP packet processed by these subsystems reaches the helper with sip_external_media enabled, dereferencing the NULL skb_dst() triggers a kernel oops or panic. The fix adds an explicit NULL check before the access, and as a side effect silently disables the sip_external_media logic for tc ingress and OVS paths.

RemediationAI

The primary fix is to upgrade to a patched Linux kernel version: 6.6.148 or later for the 6.6.x LTS branch, 6.12.101 or later for the 6.12.x LTS branch, 6.18.42 or later for the 6.18.x branch, or 7.1.5 or later for the 7.1.x branch. Stable kernel patches are available at the git.kernel.org references listed above. For systems where an immediate kernel upgrade is not feasible, the most effective compensating control is to ensure the sip_external_media module parameter remains at its default value of 0 - verify with 'cat /sys/module/nf_conntrack_sip/parameters/sip_external_media'. If it is set to 1, remove it from /etc/modprobe.d/ configurations and reload the module; this eliminates the vulnerable code path entirely and has no impact on SIP NAT traversal for standard iptables/nftables environments. Systems not using tc ingress or OpenVSwitch for SIP traffic are not exposed even with the parameter set, but patching remains recommended.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 16.0 Not-Affected

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EUVD-2026-59152 vulnerability details – vuln.today

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