Quick answers
- Is CVE-2026-33838 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-33838 being exploited in the wild.
- How severe is CVE-2026-33838?
- High severity, with a CVSS score of 7.8, published 12 May 2026.
- Which products and versions are affected?
- Microsoft Windows Message Queuing (MSMQ).
- Is there a fix for CVE-2026-33838?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-33838 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-33838?
- Check whether you run Microsoft Windows Message Queuing. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A double free vulnerability (CWE-415) exists within the Microsoft Message Queuing (MSMQ) component of Windows. The flaw is triggered when the service attempts to free the same memory location twice, leading to heap corruption. An attacker with low-privileged local access can exploit this condition to execute arbitrary code with elevated system privileges. The attack requires no user interaction but does require the attacker to have an existing account or foothold on the local system. Microsoft has released security updates to address this issue.
Affected products
- Microsoft Windows Message Queuing (MSMQ)
Timeline
- 2026-05-12: disclosed
- 2026-05-12: advisory