How severe is CVE-2018-8426?

CVE-2018-8426 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2018-8426 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8426?

CVE-2018-8426 primarily affects Microsoft Sharepoint Enterprise Server 2013. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-8426?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-8426 published?

CVE-2018-8426 was published on 2018-09-13 and last updated on 2026-06-17.

CVE-2018-8426

CVE-2018-8426 is a medium-severity vulnerability in Microsoft Sharepoint Enterprise Server 2013 with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Microsoft Sharepoint Enterprise Server 2013
Published: 2018-09-13
Last modified: 2026-06-17

Description

A cross-site-scripting (XSS) vulnerability exists when Microsoft SharePoint Server does not properly sanitize a specially crafted web request to an affected SharePoint server, aka "Microsoft Office SharePoint XSS Vulnerability." This affects Microsoft SharePoint Server, Microsoft SharePoint.

Frequently asked questions

What is CVE-2018-8426?: A cross-site-scripting (XSS) vulnerability exists when Microsoft SharePoint Server does not properly sanitize a specially crafted web request to an affected SharePoint server, aka "Microsoft Office SharePoint XSS Vulnerability." This affects Microsoft SharePoint Server, Microsoft SharePoint.
How severe is CVE-2018-8426?: CVE-2018-8426 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2018-8426 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8426?: CVE-2018-8426 primarily affects Microsoft Sharepoint Enterprise Server 2013. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-8426?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-8426 published?: CVE-2018-8426 was published on 2018-09-13 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:microsoft:sharepoint_enterprise_server_2013:-:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:sharepoint_enterprise_server_2016:-:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:sharepoint_server_2010:-:sp2:*:*:*:*:*:*

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