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Vulnerabilities

Vulnerability · CVE-2026-7423

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…

Published Apr 29, 2026 · catalog updated Jun 17, 2026 · the affected product

Last checked Oct 25, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-7423. EPSS is 0.22%. Act only if a listed version of the affected product is installed.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.22%
Remediation
Advisory link
Affected products
cpe amazon/freertos-plus-tcp

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe amazon/freertos-plus-tcpversion unspecified

How to fix CVE-2026-7423

  • No stored fix

    No vendor fix text is stored. Use the linked advisory before you change production.

  • Version check

    No version range is stored, so an installed version cannot be checked on this page.

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-7423. EPSS is 0.22%. Act only if a listed version of the affected product is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-191: Integer Underflow. EPSS 0.22%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 29, 2026 · NIST NVD

    Detected

    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. T

  2. Jun 17, 2026 · NIST NVD

    Updated

    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. T

Sources

  • CVE.orgVulnerability recordCVE-2026-7423

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-7423

    30-day exploitation probability 0.22%

    first.org
  • NIST NVDVulnerability recordCVE-2026-7423

    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 f

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 25, 2026
  • CVE.orgOct 16, 2026
  • NIST NVDOct 15, 2026