CVE-2026-7424: CWE-191: Integer Underflow (Wrap or Wraparound) in AWS FreeRTOS-Plus-TCP
CVE-2026-7424 is an integer underflow vulnerability in the DHCPv6 sub-option parser of AWS FreeRTOS-Plus-TCP versions prior to 4.4.1 and 4.2.6. This flaw allows an adjacent network actor to corrupt IPv6 address assignment, DNS configuration, and lease times. It can also cause a denial of service by freezing the IP task, requiring a hardware reset. The vulnerability exists whenever DHCPv6 is enabled. AWS has released fixed versions 4.2.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-7424) involves an integer underflow (CWE-191) in the DHCPv6 sub-option parser component of AWS FreeRTOS-Plus-TCP. Versions before 4.4.1 and 4.2.6 are affected. An adjacent network attacker can exploit this flaw to corrupt critical network configuration parameters such as IPv6 address assignment, DNS settings, and DHCP lease times. Additionally, exploitation can lead to a denial of service by causing the IP task to freeze, necessitating a hardware reset. The vulnerability is present only when DHCPv6 is enabled. AWS has released patched versions 4.2.6 and 4.4.1 to remediate the issue. The CVSS v3.1 score is 8.1 (High), reflecting the potential for integrity and availability impacts without requiring user interaction or privileges.
Potential Impact
An attacker on an adjacent network can exploit this vulnerability to corrupt IPv6 network configuration parameters, including address assignment, DNS configuration, and lease times. This corruption can disrupt network functionality and cause denial of service by freezing the IP task, which requires a hardware reset to recover. The impact affects device availability and network integrity but does not directly affect confidentiality. The vulnerability is exploitable without privileges or user interaction.
Mitigation Recommendations
AWS has released fixed versions 4.2.6 and 4.4.1 of FreeRTOS-Plus-TCP that address this vulnerability. Users should upgrade to these versions to remediate the issue. Since this is a cloud service component, AWS manages remediation for cloud-hosted instances, but embedded device users must apply the patches. Check the AWS security advisory at https://aws.amazon.com/security/security-bulletins/2026-022-aws/ for the latest remediation guidance and patch availability.
CVE-2026-7424: CWE-191: Integer Underflow (Wrap or Wraparound) in AWS FreeRTOS-Plus-TCP
Description
CVE-2026-7424 is an integer underflow vulnerability in the DHCPv6 sub-option parser of AWS FreeRTOS-Plus-TCP versions prior to 4.4.1 and 4.2.6. This flaw allows an adjacent network actor to corrupt IPv6 address assignment, DNS configuration, and lease times. It can also cause a denial of service by freezing the IP task, requiring a hardware reset. The vulnerability exists whenever DHCPv6 is enabled. AWS has released fixed versions 4.2.
CVSS v3.1
Score 8.1high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-7424) involves an integer underflow (CWE-191) in the DHCPv6 sub-option parser component of AWS FreeRTOS-Plus-TCP. Versions before 4.4.1 and 4.2.6 are affected. An adjacent network attacker can exploit this flaw to corrupt critical network configuration parameters such as IPv6 address assignment, DNS settings, and DHCP lease times. Additionally, exploitation can lead to a denial of service by causing the IP task to freeze, necessitating a hardware reset. The vulnerability is present only when DHCPv6 is enabled. AWS has released patched versions 4.2.6 and 4.4.1 to remediate the issue. The CVSS v3.1 score is 8.1 (High), reflecting the potential for integrity and availability impacts without requiring user interaction or privileges.
Potential Impact
An attacker on an adjacent network can exploit this vulnerability to corrupt IPv6 network configuration parameters, including address assignment, DNS configuration, and lease times. This corruption can disrupt network functionality and cause denial of service by freezing the IP task, which requires a hardware reset to recover. The impact affects device availability and network integrity but does not directly affect confidentiality. The vulnerability is exploitable without privileges or user interaction.
Mitigation Recommendations
AWS has released fixed versions 4.2.6 and 4.4.1 of FreeRTOS-Plus-TCP that address this vulnerability. Users should upgrade to these versions to remediate the issue. Since this is a cloud service component, AWS manages remediation for cloud-hosted instances, but embedded device users must apply the patches. Check the AWS security advisory at https://aws.amazon.com/security/security-bulletins/2026-022-aws/ for the latest remediation guidance and patch availability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-04-29T14:27:50.756Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://aws.amazon.com/security/security-bulletins/2026-022-aws/","vendor":"AWS"}]
- Is Cloud Service
- true
Threat ID: 69f256b0cbff5d86103eb491
Added to database: 4/29/2026, 7:06:24 PM
Last enriched: 6/5/2026, 7:27:24 PM
Last updated: 6/13/2026, 6:11:15 AM
Views: 71
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