Read the docs
TI-2026-06527 Aliases CVE-2026-7424

Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP

Priority LOW 33CWE-191Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00223 12th percentileScored 2026-11-07
Fix Fixed FreeRTOS-Plus-TCP (AWS): 4.2.6, 4.4.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
AWSFreeRTOS-Plus-TCP4.0.0 to before 4.2.6; 4.3.0 to before 4.4.14.2.6, 4.4.1Patch availableCNA
  • FreeRTOS-Plus-TCP VendorAWS Affected 4.0.0 to before 4.2.6; 4.3.0 to before 4.4.1 Fixed in 4.2.6, 4.4.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*4.0.0 to before 4.2.6; 4.3.0 to before 4.4.1VulnerableAWS
  • cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:* Versions 4.0.0 to before 4.2.6; 4.3.0 to before 4.4.1 Vulnerable ·AWS

Remediation

  • Fix · CNA FreeRTOS-Plus-TCP (AWS) Fixed in 4.2.6, 4.4.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-7424

References

Patch 2

Advisory 2

  • TI-2024-25630 FreeRTOS-Plus-TCP Buffer Over-Read in DNS Response Parser CVSS 3.1CRITICAL 9.6
  • TI-2026-06525 MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing CVSS 4.0HIGH 7.1
  • TI-2026-06529 Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP CVSS 4.0MEDIUM 6.1
  • TI-2026-06528 Out-of-Bounds Read in Router Advertisement Option Parser in FreeRTOS-Plus-TCP CVSS 4.0MEDIUM 6.0
  • TI-2026-06526 Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP CVSS 4.0MEDIUM 6.0
  • TI-2025-10648 Invalid Pointer Dereference when receiving UDP/IPv6 packets in FreeRTOS-Plus-TCP CVSS 4.0MEDIUM 5.3
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences