CVE-2026-7423
Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP
- State
- Published
- Severity
- 6.0 Medium
- Published
- Apr 29, 2026
- Updated
- Apr 29, 2026
- Reserved
- Apr 29, 2026
Description
Integer underflow in the ICMP and ICMPv6 echo reply handlers in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network user to cause a denial of service (device crash) when outgoing ping support is enabled, because header sizes are subtracted from a packet length field without validating the field is large enough, resulting in a heap out-of-bounds read of up to approximately 65KB.
To mitigate this issue, users should upgrade to the fixed version when available.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.0 Medium | CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | AMZN |
| 3.1 | 5.3 Medium | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | AMZN |
Weaknesses
- CWE-191 Integer Underflow (Wrap or Wraparound)
Affected Products
| Product | Versions |
|---|---|
FreeRTOS-Plus-TCPAWS |
|
References
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1patch
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6patch
- https://aws.amazon.com/security/security-bulletins/2026-021-aws/vendor-advisory
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-7r59-2pgv-9v2rthird-party-advisory
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