8.1

CVE-2026-7426: amazon freertos-plus-tcp Out-of-bounds Write

CVSS: 8.1v3.1HighAnalyzed
Published 29-04-2026Last modified 29-04-2026
Open JSON

Vulnerability summary

CVE-2026-7426 is a high (CVSS 8.1) Out-of-bounds Write vulnerability in amazon freertos-plus-tcp. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.6% of scored vulnerabilities.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.40%
0%100%
Low · +0.15 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 29-04-2026
    PublishedVulnerability first disclosed.
  2. 29-04-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

+0.15 pp

From 0.25% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Amazon1 product
Aws1 product

2 vendors · 2 products

References

4 links