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CVE-2026-7423

Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP

Published: Apr 29, 2026Updated: May 4, 2026 Sources: CVE List NVDCWE-191
5.3MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 87.6%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:AAC:HPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:AAttack Vector
Adjacent
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-191

Affected Products

freertos-plus-tcpamazonICS / OT / IoT
FreeRTOS-Plus-TCPAWS
EmbeddedLibrary
Cloud & SaaS
amazoncommercialUSCloud & SaaS
awscommercialUSCloud & SaaSaka aws

Exploitability

Official Patch Available

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://aws.amazon.com/security/security-bulletins/2026-021-aws/
aws.amazon.com
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6
github.com
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1
github.com
and 1 more references View all →

Timeline

Published
Apr 29, 2026
Last Updated
May 4, 2026

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