How severe is CVE-2018-0803?

CVE-2018-0803 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2018-0803 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-0803?

CVE-2018-0803 affects Microsoft Edge. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-0803?

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

When was CVE-2018-0803 published?

CVE-2018-0803 was published on 2018-01-04 and last updated on 2026-06-17.

CVE-2018-0803

CVE-2018-0803 is a medium-severity vulnerability in Microsoft Edge with a CVSS 3.x base score of 4.2. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
CVSS v2: 5.8
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Microsoft Edge
Published: 2018-01-04
Last modified: 2026-06-17

Description

Microsoft Edge in Microsoft Windows 10 Gold, 1511, 1607, 1703, 1709, and Windows Server 2016 allows an attacker to access information from one domain and inject it into another domain, due to how Microsoft Edge enforces cross-domain policies, aka "Microsoft Edge Elevation of Privilege Vulnerability".

Frequently asked questions

What is CVE-2018-0803?: Microsoft Edge in Microsoft Windows 10 Gold, 1511, 1607, 1703, 1709, and Windows Server 2016 allows an attacker to access information from one domain and inject it into another domain, due to how Microsoft Edge enforces cross-domain policies, aka "Microsoft Edge Elevation of Privilege Vulnerability".
How severe is CVE-2018-0803?: CVE-2018-0803 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2018-0803 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-0803?: CVE-2018-0803 affects Microsoft Edge. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-0803?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-0803 published?: CVE-2018-0803 was published on 2018-01-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:microsoft:edge:-:*:*:*:*:*:*:*

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