CVE-2026-43080Public exploit

Local service interruption via truncated UDP length

Published May 6, 2026 · Updated May 6, 2026

Integer overflow in the Linux Kernel L2TP transmit path allows local users to interrupt service through an oversized UDP-encapsulated PPP packet. l2tp_xmit_core assigns a length exceeding 65,535 bytes to the 16-bit UDP length field without checking for overflow, truncating the value before transmission. A local low-privileged user with access to a PPPoL2TP socket can trigger the availability-only impact without user interaction.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in the Linux Kernel L2TP transmit path allows local users to interrupt service through an oversized UDP-encapsulated PPP packet. l2tp_xmit_core assigns a length exceeding 65,535 bytes to the 16-bit UDP length field without checking for overflow, truncating the value before transmission. A local low-privileged user with access to a PPPoL2TP socket can trigger the availability-only impact without user interaction.

The record

CVE
CVE-2026-43080
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-674, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=2.6.23
  2. Affected versionversion=3557baabf28088f49bdf72a048fd33ab62e205b1 <77c1489398c85a844f90205f5e76fd6bc8bb4089
  3. Affected versionversion=3557baabf28088f49bdf72a048fd33ab62e205b1 <86534c97abd6365a9a021fd767a2023e63c44469
  4. Affected versionversion=3557baabf28088f49bdf72a048fd33ab62e205b1 <9ccce02d501335f59a02f26c878c5e095b16302f
  5. Affected versionversion=3557baabf28088f49bdf72a048fd33ab62e205b1 <ebe560ea5f54134279356703e73b7f867c89db13
  6. Affected versionversion=3557baabf28088f49bdf72a048fd33ab62e205b1 <f295fe86e22ff0a2ecebf05e30a387e5cf6f6ddc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.23; version=3557baabf28088f49bdf72a048fd33ab62e205b1 <77c1489398c85a844f90205f5e76fd6bc8bb4089; version=3557baabf28088f49bdf72a048fd33ab62e205b1 <86534c97abd6365a9a021fd767a2023e63c44469; version=3557baabf28088f49bdf72a048fd33ab62e205b1 <9ccce02d501335f59a02f26c878c5e095b16302f; version=3557baabf28088f49bdf72a048fd33ab62e205b1 <ebe560ea5f54134279356703e73b7f867c89db13; version=3557baabf28088f49bdf72a048fd33ab62e205b1 <f295fe86e22ff0a2ecebf05e30a387e5cf6f6ddc

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499Endpoint Denial of Service

Public exploit references

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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