CVE-2023-43826

Name: CVE-2023-43826
Creator: NVD / NIST
Published: 2023-12-19T20:15:08.3+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.89%

Last modified Jun 17, 2026

CVE-2023-43826 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Apache Guacamole 1.5.3 and older do not consistently ensure that values received from a VNC server will not result in integer overflow. If a user connects to a malicious or compromised VNC server, specially-crafted data could result in memory corruption, possibly allowing arbitrary code to be executed with the privileges of the running guacd process. Users are recommended to upgrade to version 1.5.4, which fixes this issue.. EPSS estimates a 0.89% chance of exploitation in the next 30 days.

Description

Apache Guacamole 1.5.3 and older do not consistently ensure that values received from a VNC server will not result in integer overflow. If a user connects to a malicious or compromised VNC server, specially-crafted data could result in memory corruption, possibly allowing arbitrary code to be executed with the privileges of the running guacd process. Users are recommended to upgrade to version 1.5.4, which fixes this issue.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

0.89%

54.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-190

Affected Software

Vendor	Product	Versions
Apache	Guacamole	<= 1.5.3

References

http://www.openwall.com/lists/oss-security/2023/12/19/4Mailing List, Third Party Advisory
https://lists.apache.org/thread/23gzwftpfgtq97tj6ttmbclry53kmwv6Mailing List, Vendor Advisory
http://www.openwall.com/lists/oss-security/2023/12/19/4Mailing List, Third Party Advisory
https://lists.apache.org/thread/23gzwftpfgtq97tj6ttmbclry53kmwv6Mailing List, Vendor Advisory

Timeline

Published: Dec 19, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-43826?

How severe is CVE-2023-43826?

CVE-2023-43826 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.89% probability of exploitation in the next 30 days.

How do I fix CVE-2023-43826?

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-2023-43826?

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

Scan your code now

Source: NVD / NIST