Integer underflow in the DHCPv6 sub-option parser in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network actor to corrupt the device's IPv6 address assignment, DNS configuration, and lease times, and to cause a denial of service (permanent IP task freeze requiring hardware reset) by sending a single crafted DHCPv6 packet.








The issue is present whenever DHCPv6 is enabled.








To mitigate this issue, users should upgrade to version V4.2.6 or V4.4.1 or newer.

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
AWS FreeRTOS-Plus-TCP unaffected
Version Status Constraints
4.0.0 affected < 4.2.6
4.3.0 affected < 4.4.1
4.2.6 unaffected —
4.4.1 unaffected —

No data.

No data.

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://aws.amazon.com/security/security-bulletins/2026-022-aws/ cve-icon cve-icon
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6 cve-icon cve-icon
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1 cve-icon cve-icon
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-wrhm-c99p-2p8g cve-icon cve-icon
History

Wed, 29 Apr 2026 22:45:00 +0000

Type Values Removed Values Added
References

Wed, 29 Apr 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Wed, 29 Apr 2026 19:00:00 +0000

Type Values Removed Values Added
Description Integer underflow in the DHCPv6 sub-option parser in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network actor to corrupt the device's IPv6 address assignment, DNS configuration, and lease times, and to cause a denial of service (permanent IP task freeze requiring hardware reset) by sending a single crafted DHCPv6 packet. The issue is present whenever DHCPv6 is enabled. To mitigate this issue, users should upgrade to version V4.2.6 or V4.4.1 or newer.
Title Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP
Weaknesses CWE-191
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H'}

cvssV4_0

{'score': 7.2, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-04-29T22:13:39.794Z

Reserved: 2026-04-29T14:27:50.756Z

Link: CVE-2026-7424

cve-icon Vulnrichment

Updated: 2026-04-29T19:08:57.950Z

cve-icon NVD

Status : Received

Published: 2026-04-29T19:16:26.743

Modified: 2026-04-29T23:16:20.367

Link: CVE-2026-7424

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-29T21:15:16Z

Weaknesses