PatchSiren cyber security CVE debrief

CVE-2023-43688 Malwarebytes CVE debrief

CVE-2023-43688 is a HIGH severity vulnerability in Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later). An issue was discovered in Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later). There is a Heap buffer overflow in various buffer encryption utilities. The CVSS score for this vulnerability is 7.5.

Vendor: Malwarebytes
Product: Malwarebytes 4.x and 5.x (including Nebula 2020‑10‑21 and later)
CVSS: HIGH 7.5
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-09
Original CVE updated: 2026-06-09
Advisory published: 2026-06-09
Advisory updated: 2026-06-09

Who should care

Users of Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later) should be aware of this HIGH severity vulnerability and take action to mitigate it.

Technical summary

The vulnerability is caused by a Heap buffer overflow in various buffer encryption utilities in Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later).

Defensive priority

HIGH

Recommended defensive actions

Apply patches or updates provided by the vendor to fix the vulnerability.
Use secure practices when using Malwarebytes 4.x and 5.x (and Nebula 2020-10-21 and later).

Evidence notes

The CVE was published on 2026-06-09T19:16:42.060Z and last modified on 2026-06-09T21:17:01.950Z.

Official resources

CVE-2023-43688 was published on 2026-06-09T19:16:42.060Z.