6.5

CVE-2026-7423: amazon freertos-plus-tcp Integer Underflow (Wrap or Wraparound)

CVSS: 6.5v3.1MediumAnalyzed
Published 29-04-2026Last modified 29-04-2026
Open JSON

Vulnerability summary

CVE-2026-7423 is a medium (CVSS 6.5) Integer Underflow (Wrap or Wraparound) vulnerability in amazon freertos-plus-tcp. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.36%
0%100%
Low · +0.14 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

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.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

+0.14 pp

From 0.22% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.36%

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