CVE-2026-7424

Device configuration corruption and IP-task freeze via underflow

Published Apr 29, 2026 · Updated Apr 29, 2026

Integer underflow in FreeRTOS-Plus-TCP 4.0.0 through 4.2.5 and 4.3.0 through 4.4.0 allows attackers to freeze the IP task. In prvDHCPv6_subOption(), the unknown sub-option path subtracts the cumulative parent-byte count from an unsigned payload length and passes the wrapped skip length to xBitConfig_read_uc(), corrupting parser state. DHCPv6 must be enabled, and one crafted packet from the adjacent network can corrupt IPv6 addressing, DNS settings, and lease times before the task freezes until hardware reset.

CVSS severity7.2
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in FreeRTOS-Plus-TCP 4.0.0 through 4.2.5 and 4.3.0 through 4.4.0 allows attackers to freeze the IP task. In prvDHCPv6_subOption(), the unknown sub-option path subtracts the cumulative parent-byte count from an unsigned payload length and passes the wrapped skip length to xBitConfig_read_uc(), corrupting parser state. DHCPv6 must be enabled, and one crafted packet from the adjacent network can corrupt IPv6 addressing, DNS settings, and lease times before the task freezes until hardware reset.

The record

CVE
CVE-2026-7424
Published
Apr 29, 2026
Updated
Apr 29, 2026
Vendor
Amazon Web Services
Product
FreeRTOS-Plus-TCP
Classifications
CWE-191, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 29, 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=4.0.0 <4.2.6
  2. Affected versionversion=4.3.0 <4.4.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Amazon Web Services · FreeRTOS-Plus-TCPversion=4.0.0 <4.2.6; version=4.3.0 <4.4.1

Published CVSS scores

7.2Amazon Web ServicesCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
8.1Amazon Web ServicesCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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