CVE-2026-53070Network attack vector

Service degradation via unbalanced per-CPU recursion counters

Published Jun 24, 2026 · Updated Jun 24, 2026

A transmit-path flaw in the Linux Kernel allows remote attackers to cause packet loss via SCTP-over-UDP traffic on affected systems. The IPv4 and IPv6 SCTP UDP transmit paths call udp_tunnel_xmit_skb() without disabling bottom halves, so CPU migration can unbalance per-CPU recursion increments and decrements. SCTP UDP encapsulation must be enabled and exercised; incorrect recursion detection then drops packets in IP tunnel transmission or device queuing, degrading service without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A transmit-path flaw in the Linux Kernel allows remote attackers to cause packet loss via SCTP-over-UDP traffic on affected systems. The IPv4 and IPv6 SCTP UDP transmit paths call udp_tunnel_xmit_skb() without disabling bottom halves, so CPU migration can unbalance per-CPU recursion increments and decrements. SCTP UDP encapsulation must be enabled and exercised; incorrect recursion detection then drops packets in IP tunnel transmission or device queuing, degrading service without reported data disclosure or modification.

The record

CVE
CVE-2026-53070
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=046c052b475e7119b6a30e3483e2888fc606a2f8 <2cd7e6971fc2787408ceef17906ea152791448cf
  2. Affected versionversion=046c052b475e7119b6a30e3483e2888fc606a2f8 <790093245e35040c2adb15f48970020425aa3f47
  3. Affected versionversion=5.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=046c052b475e7119b6a30e3483e2888fc606a2f8 <2cd7e6971fc2787408ceef17906ea152791448cf; version=046c052b475e7119b6a30e3483e2888fc606a2f8 <790093245e35040c2adb15f48970020425aa3f47; version=5.11

Published CVSS scores

7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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