CVE-2026-93204

ARP cache poisoning via non-atomic MAC updates

Published Sep 17, 2026 · Updated Oct 3, 2026

ARP cache poisoning in Linux kernels from 3.8 allows context-dependent attackers to corrupt mesh ARP responses through raced MAC updates. In batman-adv's batadv_dat_entry_add(), a plain copy updates a distributed ARP table MAC address while parallel readers can observe a mixture of its old and new bytes. The failure requires an active batman-adv mesh, use of its distributed ARP table, and a concurrent address update; the resulting incorrect mapping can disrupt traffic on that mesh.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

ARP cache poisoning in Linux kernels from 3.8 allows context-dependent attackers to corrupt mesh ARP responses through raced MAC updates. In batman-adv's batadv_dat_entry_add(), a plain copy updates a distributed ARP table MAC address while parallel readers can observe a mixture of its old and new bytes. The failure requires an active batman-adv mesh, use of its distributed ARP table, and a concurrent address update; the resulting incorrect mapping can disrupt traffic on that mesh.

The record

CVE
CVE-2026-93204
Published
Sep 17, 2026
Updated
Oct 3, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1557.002
Attack vector
adjacent
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <159360a0de831845c4500b4f8638decdcd624040
  2. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <1674855a5b6eacfe35f4db3095d7055c25467274
  3. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <181012b3d29c51197c235ee5871fc7512c736855
  4. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <259db2c04586d40b82c5c3002b1e28b0698a0bb7
  5. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <66238e2a74eca5dabf85b0cd2c3c944e474dc2fd
  6. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <a5e4d6cb4f6848b8906c1c493f99a8ccc0638515
  7. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <e6de568d3eda3e3c01c868fabd7a9535d5ee4a73
  8. Affected versionversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <f68038c77a2f38c09c7e2e4f7fa1f4e246fdf2c9
  9. Affected versionversion=3.8

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=2f1dfbe185075a50dc8f0490a136377af53a1c62 <159360a0de831845c4500b4f8638decdcd624040; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <1674855a5b6eacfe35f4db3095d7055c25467274; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <181012b3d29c51197c235ee5871fc7512c736855; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <259db2c04586d40b82c5c3002b1e28b0698a0bb7; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <66238e2a74eca5dabf85b0cd2c3c944e474dc2fd; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <a5e4d6cb4f6848b8906c1c493f99a8ccc0638515; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <e6de568d3eda3e3c01c868fabd7a9535d5ee4a73; version=2f1dfbe185075a50dc8f0490a136377af53a1c62 <f68038c77a2f38c09c7e2e4f7fa1f4e246fdf2c9; version=3.8

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1557.002Adversary-in-the-Middle: ARP Cache Poisoning

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

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started