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

udp: call skb_orphan() before skb_attempt_defer_free()

Standard UDP receive path does not use skb->destructor.

But skmsg layer does use it, since it calls skb_set_owner_sk_safe()
from udp_read_skb().

This then triggers this warning in skb_attempt_defer_free():

DEBUG_NET_WARN_ON_ONCE(skb->destructor);

We must call skb_orphan() to fix this issue.
Published: 2026-02-04
Score: 7.0 High
EPSS: < 1% Very Low
KEV: No
Impact: Kernel memory corruption that could lead to privilege escalation or system crash
Action: Apply patch
AI Analysis

Impact

The flaw arises from a mismatch in the handling of socket buffers during UDP packet reception. The path does not invoke the skb->destructor field, while the skmsg layer does, leading to a defensive warning in skb_attempt_defer_free(). This discrepancy can result in a double free or use‑after‑free condition, classified as CWE‑416, and may corrupt kernel memory. If exploited, an attacker could potentially gain elevated privileges or crash the operating system.

Affected Systems

The vulnerability is present in the Linux kernel itself. Vendors and product families include Linux: Linux kernel, covering all compiled kernel images built from the mainline source. No explicit build or version range is specified, so any kernel that has not applied the upstream patch may be susceptible until updated.

Risk and Exploitability

The CVSS score of 7.0 indicates a high severity vulnerability, yet the EPSS score of less than 1% suggests that exploitation in the wild is currently very unlikely. The flaw is not listed in the CISA KEV catalog, further supporting the low deployment risk. The most probable attack vector is remote, using crafted UDP packets that reach processes handling network traffic. Exploitation would likely require precise timing and could demand that the attacker has network connectivity to the target system or access to services that observe UDP traffic. Even so, a successful exploit would result in kernel memory corruption, potentially allowing privilege escalation or denial of service.

Generated by OpenCVE AI on April 18, 2026 at 19:46 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the Linux kernel to a release that includes the CVE-2026-23048 fix
  • Reboot the system to load the updated kernel
  • If immediate patching is not feasible, limit or filter UDP traffic to non‑essential ports to reduce exposure

Generated by OpenCVE AI on April 18, 2026 at 19:46 UTC.

Tracking

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Advisories

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History

Sat, 18 Apr 2026 20:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Thu, 05 Feb 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Wed, 04 Feb 2026 16:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: udp: call skb_orphan() before skb_attempt_defer_free() Standard UDP receive path does not use skb->destructor. But skmsg layer does use it, since it calls skb_set_owner_sk_safe() from udp_read_skb(). This then triggers this warning in skb_attempt_defer_free(): DEBUG_NET_WARN_ON_ONCE(skb->destructor); We must call skb_orphan() to fix this issue.
Title udp: call skb_orphan() before skb_attempt_defer_free()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-02-09T08:37:43.601Z

Reserved: 2026-01-13T15:37:45.949Z

Link: CVE-2026-23048

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-02-04T16:16:20.343

Modified: 2026-04-15T00:35:42.020

Link: CVE-2026-23048

cve-icon Redhat

Severity : Important

Publid Date: 2026-02-04T00:00:00Z

Links: CVE-2026-23048 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-18T20:00:09Z

Weaknesses