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CVE Record

CVE-2026-23048: udp: call skb_orphan() before skb_attempt_defer_free()

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2026-23048 is a Linux kernel UDP handling issue. The public description says a specific UDP/skmsg receive path can leave a packet buffer destructor set before deferred freeing, triggering a kernel networking warning. Public sources do not state data theft, privilege escalation, service disruption impact, or active exploitation.

Executive priority

Treat as a kernel hygiene item pending vendor confirmation. There is no public evidence of exploitation or severe impact in the supplied sources, but kernel issues can have broad operational reach. Patch through normal Linux kernel maintenance once your vendor ships or confirms the fix.

Technical view

In the Linux kernel UDP receive path, skmsg uses skb_set_owner_sk_safe() from udp_read_skb(), setting skb->destructor. skb_attempt_defer_free() warns when a destructor remains. The fix calls skb_orphan() before skb_attempt_defer_free(). The affected data indicates Linux kernel 6.18/6.19-related versions, but exact downstream package exposure depends on vendor backports.

Likely exposure

Exposure is likely limited to systems running affected Linux kernel builds that include the vulnerable UDP/skmsg code path. Distribution kernels may differ because vendors backport fixes or carry custom patches. Confirm against your OS vendor’s kernel advisories and package changelogs.

Exploitation context

No cited source reports active exploitation, and the CVE is not marked KEV. The public record describes a kernel warning condition, not a complete exploit scenario. Preconditions, attacker reachability, and practical security impact are not fully documented in the provided sources.

Researcher notes

The public record is sparse: no CVSS, CWE, exploitability analysis, or detailed affected downstream list. The core change is ordering skb_orphan() before deferred free to clear ownership/destructor state. Avoid over-scoping impact without reviewing the exact kernel branch and vendor backports.

Mitigation direction

  • Check your Linux distribution or appliance vendor advisory for CVE-2026-23048 guidance.
  • Prioritize kernel updates that include the referenced stable commits.
  • If updates are unavailable, ask the vendor whether affected UDP/skmsg code is present.
  • Track reboot requirements for kernel package updates.

Validation and detection

  • Inventory running Linux kernel versions across servers, containers hosts, and appliances.
  • Compare installed kernel packages with vendor advisories for CVE-2026-23048.
  • Verify whether referenced stable commit IDs are included in your kernel source or changelog.
  • Monitor kernel logs for related networking warnings while awaiting vendor guidance.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2026-23048 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
3Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux6471658dc66c670580a7616e75f51b52917e7883, 6471658dc66c670580a7616e75f51b52917e7883unaffected
LinuxLinux6.18, 0, 6.18.6, 6.19affected
Weakness

CWE details

No CWE listed

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