Buffer overflow in Amazon Freertos-Plus-Tcp
CVE-2026-7426
Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted. To mitigate this issue, users should upgrade to the fixed version when available.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (31.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Amazon Freertos-Plus-Tcp
- AWS Freertos-Plus-Tcp — versions 4.0.0, 4.3.0, 4.2.6
Weakness classification (CWE)
References
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory, Vendor Advisory)
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (patch, Release Notes)
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (patch, Release Notes)
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (Patch, third-party-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-7426?
- CVE-2026-7426 is a high-severity vulnerability in Amazon Freertos-Plus-Tcp, classified under Out-of-bounds Write. CVSS score: 8.1/10. Published 2026-04-29.
- How severe is CVE-2026-7426?
- High severity. CVSS v3 base score is 8.1 out of 10.