CVE-2026-77910
HighCVSS 8.8Summary
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
Risk Assessment
Risk of unauthorized access to mailboxes and data, potentially leading to confidentiality breaches.
Recommendation
Apply Exchange Server security updates and review permission configurations to restrict access to sensitive resources.
Other vulnerabilities in Microsoft Exchange Server
See all- CVE-2026-87696High
Improper verification of cryptographic signature in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- CVE-2026-87695High
A vulnerability in Microsoft Exchange Server involves inclusion of functionality from an untrusted control sphere. An authorized attacker can elevate privileges locally.
- CVE-2026-87692High
A deserialization of untrusted data vulnerability in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
- CVE-2026-70571High
Stack-based buffer overflow in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
- CVE-2026-70279Critical
Improper neutralization of input during web page generation (cross-site scripting) in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
- CVE-2026-69641Critical
Missing authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- CVE-2026-69356Critical
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
- CVE-2026-55008Critical
A cross-site scripting (XSS) vulnerability in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network. The flaw is due to improper neutralization of input during web page generation.
- CVE-2026-45502Medium
A Server-Side Request Forgery (SSRF) vulnerability in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.
- CVE-2026-42897HighActively exploited
Microsoft Exchange Server has an improper neutralization of input during web page generation, leading to a cross-site scripting vulnerability. This flaw allows an unauthorized attacker to perform spoofing over a network.
Original NVD description (English source)
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS