Medium severity · published Apr 29, 2026
CVE-2026-7422
MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing
6.5
CVSS
0.2%
EPSS
No
On KEV
Description
Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match one of the device's own registered endpoints, because the loopback detection mechanism skips all input validation for packets whose source MAC matches a local endpoint.
To mitigate this issue, users should upgrade to the fixed version when available.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeRTOS-Plus-TCP · AWS
4.0.0 before 4.2.6; 4.3.0 before 4.4.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-7422
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-7422
Vendor Advisory
https://aws.amazon.com/security/security-bulletins/2026-021-aws/
Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6
Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1
Patch
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-jpw4-6h59-62w9
More from FreeRTOS-Plus-TCP
8.1
CVE-2026-7426
Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP
8.1
CVE-2026-7424
Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP
6.5
CVE-2026-7425
Out-of-Bounds Read in Router Advertisement Option Parser in FreeRTOS-Plus-TCP
6.5
CVE-2026-7423
Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP