CVE-2021-26788

Name: CVE-2021-26788
Creator: NVD / NIST
Published: 2021-03-08T13:15:12.737+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.22%

Last modified Jun 17, 2026

CVE-2021-26788 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Oryx Embedded CycloneTCP 1.7.6 to 2.0.0, fixed in 2.0.2, is affected by incorrect input validation, which may cause a denial of service (DoS). To exploit the vulnerability, an attacker needs to have TCP connectivity to the target system. EPSS estimates a 1.22% chance of exploitation in the next 30 days.

Description

Oryx Embedded CycloneTCP 1.7.6 to 2.0.0, fixed in 2.0.2, is affected by incorrect input validation, which may cause a denial of service (DoS). To exploit the vulnerability, an attacker needs to have TCP connectivity to the target system. Receiving a maliciously crafted TCP packet from an unauthenticated endpoint is sufficient to trigger the bug.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.22%

64.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Oryx-Embedded	Cyclonetcp	>= 1.7.6, <= 2.0.0

References

https://github.com/Oryx-Embedded/CycloneTCP/commit/de5336016edbe1e90327d0ed1cba5c4e49114366?branch=de5336016edbe1e90327d0ed1cba5c4e49114366&diff=splitPatch, Third Party Advisory
https://github.com/Oryx-Embedded/CycloneTCP/commit/de5336016edbe1e90327d0ed1cba5c4e49114366?branch=de5336016edbe1e90327d0ed1cba5c4e49114366&diff=splitPatch, Third Party Advisory

Timeline

Published: Mar 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26788?

How severe is CVE-2021-26788?

CVE-2021-26788 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.22% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26788?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26788?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST