CVE-2026-118150: Microsoft Exchange Server authorization bypass in authentication

CVE-2026-118150 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Exchange Server, which handles corporate email and calendaring, contains an authorization bypass flaw that allows an authenticated attacker to escalate their privileges within the system. An attacker with valid credentials could bypass security controls and gain elevated access to sensitive email and organizational data.

Technologies: Microsoft Exchange Server. Vendors: Microsoft.

Quick answers

Is CVE-2026-118150 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-118150 being exploited in the wild.
How severe is CVE-2026-118150?
High severity, with a CVSS score of 8.8, published 10 November 2026.
Which products and versions are affected?
Microsoft Exchange Server.
Is there a fix for CVE-2026-118150?
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-2026-118150 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-118150?
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

A user-controlled key vulnerability in Microsoft Exchange Server permits authorization bypass when an authenticated attacker can manipulate authentication parameters. The attack requires network access and valid credentials to exploit, but once successful grants privilege escalation over the network to affected Exchange deployments.

Affected products

  • Microsoft Exchange Server

Timeline

  • 2026-11-10: disclosed

References

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