Quick answers
- Is CVE-2026-55007 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-55007 being exploited in the wild.
- How severe is CVE-2026-55007?
- High severity, with a CVSS score of 8.1, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Exchange Server.
- Is there a fix for CVE-2026-55007?
- 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-2026-55007 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-55007?
- Check whether you run Microsoft Exchange Server. 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
The vulnerability is a double free (memory corruption) in Microsoft Exchange Server, allowing unauthenticated remote code execution. The defect permits an attacker on the network to trigger the unsafe memory deallocation, leading to arbitrary code execution with the privileges of the Exchange process. No authentication is required and the attack is network-accessible, making it exploitable from outside the organization's perimeter. Patches are available from Microsoft via their Security Response Center.
Affected products
- Microsoft Exchange Server
Timeline
- 2026-09-08: disclosed: Published on NVD and Microsoft Security Response Center