Is CVE-2026-6621 in the CISA KEV catalog?

No. CVE-2026-6621 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-6621?

CVE-2026-6621 has a CVSS v3 base score of 7.3 (HIGH).

What is the EPSS score for CVE-2026-6621?

CVE-2026-6621 has an EPSS score of 0.34% (25th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-6621

HIGH

7.3

CVSS v3

NVD

Description

A vulnerability was determined in 1024bit extend-deep up to 0.1.6. The impacted element is an unknown function of the file index.js. This manipulation of the argument __proto__ causes improperly controlled modification of object prototype attributes. Remote exploitation of the attack is possible. The exploit has been publicly disclosed and may be utilized. The code repository of the project has not been active for many years.

CWE-94Code Injection CWE-1321

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityLow

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

Exploit Intelligence

0.34%probability of exploitation in 30 days

25thpercentile

Low risk: more likely to be exploited than 25% of all known CVEs.

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

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 2026-04-29.