Vulnerability · Published Oct 16, 2026 · Assigned by AMZN
CVE-2026-102552Improper verification of the source of a communication channel in FreeRTOS-Plus-TCP DNS resolver
Medium 5.9
In plain English
A medium-severity security flaw in FreeRTOS-Plus-TCP from FreeRTOS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).
Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)0.2%top 85.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Improper verification of the source of a communication channel in the DNS resolver in Amazon FreeRTOS-Plus-TCP before V4.4.2 might allow remote third-party to insert a chosen address into the device's DNS cache via a forged DNS reply. To remediate this issue, users should upgrade to version V4.4.2 and enable ipconfigDNS_CHECK_REPLY_SOURCE_IP.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| FreeRTOS | FreeRTOS-Plus-TCP | 0 – through 4.4.1 |
Weakness: CWE-940 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.2 release-notes, patch
- https://aws.amazon.com/security/security-bulletins/2026-139-aws/ vendor-advisory
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-h4fw-pv82-p7h5 third-party-advisory