# CVE-2026-55030: Microsoft SharePoint cross-site scripting vulnerability

Source: https://junglewise.ai/threats/cve-2026-55030-microsoft-sharepoint-cross-site-scripting-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-14. Updated: 2026-07-14  
License: CC BY 4.0 with a link back

CVE-2026-55030 · Severity: medium · CVSS 4.6 · Published 2026-07-14

Microsoft SharePoint is a widely used collaboration and document management platform for businesses. A vulnerability in how the system handles user input could allow an authorized user to perform a spoofing attack against other users. This could lead to unauthorized actions being performed in the context of a victim's session or the display of fraudulent information.

Technologies: [Microsoft SharePoint Enterprise Server 2016](https://junglewise.ai/threats/technologies/sharepoint-enterprise-server-2016), [Microsoft SharePoint Server 2019](https://junglewise.ai/threats/technologies/sharepoint-server-2019), [Microsoft SharePoint Server Subscription Edition](https://junglewise.ai/threats/technologies/sharepoint-server-subscription-edition). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-55030 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-55030 being exploited in the wild.

**How severe is CVE-2026-55030?** Medium severity, with a CVSS score of 4.6, published 14 July 2026.

**Which products and versions are affected?** Microsoft SharePoint Enterprise Server 2016 < 16.0.5561.1001; Microsoft SharePoint Server 2019 < 16.0.10417.20175; Microsoft SharePoint Server Subscription Edition < 16.0.19725.20434.

**Is there a fix for CVE-2026-55030?** 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-2026-55030 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-55030?** Check whether you run Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019 or Microsoft SharePoint Server Subscription Edition at an affected version. 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 cross-site scripting (XSS) vulnerability exists in Microsoft SharePoint due to improper neutralization of input during web page generation (CWE-79). An authenticated attacker with low privileges can exploit this by sending a specially crafted request to a vulnerable SharePoint server. Successful exploitation requires a victim to interact with a malicious link or page, allowing the attacker to execute script in the victim's browser session. This can result in unauthorized information disclosure or data modification within the scope of the victim's permissions. The vulnerability affects SharePoint Enterprise Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition.

## Affected products

- Microsoft SharePoint Enterprise Server 2016 < 16.0.5561.1001
- Microsoft SharePoint Server 2019 < 16.0.10417.20175
- Microsoft SharePoint Server Subscription Edition < 16.0.19725.20434

## Timeline

- 2026-07-14: disclosed
- 2026-07-14: advisory: Microsoft released security updates for affected versions.

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55030](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55030)

## Related threats

- [Microsoft SharePoint cross-site scripting vulnerability](https://junglewise.ai/threats/cve-2026-62826-microsoft-sharepoint-cross-site-scripting-vulnerability)
- [Microsoft SharePoint improper authorization privilege escalation](https://junglewise.ai/threats/cve-2026-58277-microsoft-sharepoint-improper-authorization-privilege-escalation)
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- [Microsoft SharePoint improper access control spoofing vulnerability](https://junglewise.ai/threats/cve-2026-56157-microsoft-sharepoint-improper-access-control-spoofing)
- [Microsoft Office Word numeric truncation information disclosure](https://junglewise.ai/threats/cve-2026-55142-microsoft-office-word-numeric-truncation-information-disclosure)