Is CVE-2026-43887 in the CISA KEV catalog?

No. CVE-2026-43887 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-43887?

CVE-2026-43887 has a CVSS v3 base score of 7.3 (HIGH).

What is the EPSS score for CVE-2026-43887?

CVE-2026-43887 has an EPSS score of 0.24% (15th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-43887

HIGH

7.3

CVSS v3

NVD

Description

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.6.1, the Outline comment section permits users to mention other users; however, the backend does not validate or sanitize the href attribute associated with these mentions. As a result, potentially dangerous protocols (e.g., javascript:) are not filtered, introducing a risk of client-side code execution. This vulnerability is fixed in 1.7.0.

CWE-79Cross-Site Scripting (XSS)

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

Exploit Intelligence

0.24%probability of exploitation in 30 days

15thpercentile

Low risk: more likely to be exploited than 15% of all known CVEs.

References

https://github.com/outline/outline/security/advisories/GHSA-rqrg-f3qc-xvgh

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-15.