Quick answers
- Is CVE-2026-69378 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-69378 being exploited in the wild.
- How severe is CVE-2026-69378?
- High severity, with a CVSS score of 7.5, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Exchange Server.
- Is there a fix for CVE-2026-69378?
- 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-2026-69378 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-69378?
- 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 an uncontrolled recursion flaw in Microsoft Exchange Server that allows remote attackers to cause a denial of service condition. The attack is network-accessible and requires no authentication or user interaction. By exploiting the recursive behavior in the affected component, an attacker can exhaust server resources and crash the service, rendering email unavailable to users. A patch is expected to be available from Microsoft through their Security Update Guide.
Affected products
- Microsoft Exchange Server
Timeline
- 2026-09-08: disclosed