SharePoint Improper Authentication Vulnerability CVE-2025-49706

Historical catalog analysis: CISA added this entry on July 22, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2025-49706 is an improper authentication vulnerability affecting Microsoft SharePoint. This flaw allows an authorized attacker to perform spoofing over a network. If successfully exploited, an attacker could view sensitive information and make changes to disclosed data.

Technical documentation indicates this vulnerability can be chained with CVE-2025-49704. Furthermore, CVE-2025-53771 has been identified as a patch bypass for CVE-2025-49706; consequently, updates addressing CVE-2025-53771 are reported to provide more robust protection than the initial fixes for CVE-2025-49706.

Exposure and applicability

This vulnerability is particularly relevant to U.S. healthcare providers and business associates who utilize on-premises SharePoint Server installations to store, manage, or collaborate on documents. Because these environments often house electronic Protected Health Information (ePHI), an attacker’s ability to spoof identities and modify information poses a risk to both data confidentiality and the integrity of patient records.

CISA has reported that this vulnerability is known to be used in ransomware campaigns, increasing the urgency for organizations to evaluate their exposure. The risk is highest for those running public-facing instances or outdated versions of the software.

Remediation priorities

Based on our analysis of the reported flaw and its exploitation patterns, we suggest the following prioritized actions:

1. Decommission End-of-Life (EOL) Systems: Immediately disconnect any public-facing SharePoint Server versions that have reached end-of-life or end-of-service status, specifically including SharePoint Server 2013 and earlier versions.
2. Apply Comprehensive Updates: For supported versions, apply vendor updates. We recommend prioritizing the updates associated with CVE-2025-53771 to address the patch bypass and ensure more robust protection than provided by the standalone CVE-2025-49706 fix.
3. Review Network Exposure: Evaluate whether on-premises SharePoint servers are unnecessarily exposed to the public internet, as this increases the likelihood of network-based spoofing attempts.

How to validate remediation

To verify that exposure has been reduced, security leaders and IT teams should perform the following checks:

• Version Audit: Confirm through system inventories that no EOL/EOS versions (2013 or earlier) remain active on public-facing network segments.
• Patch Verification: Cross-reference installed update IDs against vendor documentation to ensure that both CVE-2025-49706 and the bypass CVE-2025-53771 have been addressed.
• Connectivity Review: Validate via firewall logs or network mapping that SharePoint access is restricted to authorized paths, reducing the attack surface for network-based spoofing.

Note: A version check alone does not guarantee security but confirms the application of available vendor mitigations.

Limits and open questions

While updates are available for supported versions, organizations running EOL software have no official patch path and must rely on disconnection or migration. It remains unclear to what extent cloud-based SharePoint environments are affected compared to on-premises installations; users should verify their specific deployment model with the vendor.

Additionally, while patching reduces the likelihood of exploitation, it does not eliminate all residual risks associated with authorized attackers who may already have a foothold in the network. Organizations should continue to monitor for anomalous behavior within their document management systems.

Source and editorial note

CVE-2025-49706: Microsoft SharePoint Improper Authentication Vulnerability · Source date: July 22, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: July 25, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 05, 2026 at 00:39 UTC.

Request a healthcare security assessment