Description
Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.
Published: 2026-06-09
Score: 8.1 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability is a server‑side request forgery (SSRF) that permits an authorized attacker to disclose information over a network. The flaw is an improper authorization vulnerability in Microsoft Exchange Server that allows an authenticated attacker to read data over the network. Because the weakness is a direct breach of access control (CWE‑285), an attacker who can authenticate to the Exchange Server can gain confidentiality of data not intended for that user. The CVSS score of 8.1 reflects the high confidentiality impact of this scenario.

Affected Systems

Microsoft Exchange Server 2016 cumulative update 23, Microsoft Exchange Server 2019 cumulative update 14, Microsoft Exchange Server 2019 cumulative update 15, and Microsoft Exchange Server Subscription Edition RTM are all affected, as identified by the CNA and reflected in the CVE vendor/product listings.

Risk and Exploitability

Because the attacker must possess valid credentials, the most likely attack surface is within an internal network or through a compromised account. The likely attack vector is remote, as the information can be disclosed over a network, but this inference is drawn from the description rather than an explicit statement. No known exploits appear in CISA’s KEV catalog and EPSS data is unavailable, yet the high CVSS score indicates a significant potential for confidentiality breaches if privileged accounts are not tightly controlled.

Generated by OpenCVE AI on June 9, 2026 at 23:39 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the Microsoft cumulative update or patch that addresses CVE‑2026‑45503 to the affected Exchange Server installations.
  • If an update cannot be applied immediately, deploy firewall or network segmentation rules to block the request paths or protocols that are used to trigger the improper authorization flaw.
  • Enforce least‑privilege by limiting user rights and ensuring that only accounts that truly need access to the vulnerable features retain elevated privileges.

Generated by OpenCVE AI on June 9, 2026 at 23:39 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Tue, 09 Jun 2026 22:30:00 +0000

Type Values Removed Values Added
Description Improper authorization in Microsoft Exchange Server allows an authorized attacker to disclose information over a network. Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.

Tue, 09 Jun 2026 18:00:00 +0000

Type Values Removed Values Added
Description Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to disclose information over a network. Improper authorization in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.

Tue, 09 Jun 2026 17:15:00 +0000

Type Values Removed Values Added
Description Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.
Title Microsoft Exchange Server Information Disclosure Vulnerability
First Time appeared Microsoft
Microsoft exchange Server 2016
Microsoft exchange Server 2019
Microsoft exchange Server Se
Weaknesses CWE-285
CPEs cpe:2.3:a:microsoft:exchange_server_2016:*:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_2019:*:cumulative_update_14:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_2019:*:cumulative_update_15:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_se:*:RTM:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft exchange Server 2016
Microsoft exchange Server 2019
Microsoft exchange Server Se
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C'}


Subscriptions

Microsoft Exchange Server 2016 Exchange Server 2019 Exchange Server Se
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2026-06-09T21:49:59.219Z

Reserved: 2026-05-12T16:07:22.619Z

Link: CVE-2026-45503

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Undergoing Analysis

Published: 2026-06-09T17:17:26.137

Modified: 2026-06-09T23:16:55.070

Link: CVE-2026-45503

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-09T22:15:15Z

Weaknesses