RCE in 1024bit Extend-Deep
CVE-2026-6621
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.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.006 (44.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.006 · change: +0.002
Affected products
- 1024bit Extend-Deep — versions 0.1.0, 0.1.1, 0.1.2
Weakness classification (CWE)
References
- vuldb.com/vuln/358256 (technical-description, vdb-entry)
- vuldb.com/vuln/358256/cti (signature, permissions-required)
- vuldb.com/submit/792387 (third-party-advisory)
- github.com/sudo-secure/security-research/blob/main/extend-deep/prototype-pollut… (exploit)
Frequently asked questions
- What is CVE-2026-6621?
- CVE-2026-6621 is a high-severity vulnerability in 1024bit Extend-Deep, classified under Code Injection. CVSS score: 7.3/10. Published 2026-04-20.
- How severe is CVE-2026-6621?
- High severity. CVSS v3 base score is 7.3 out of 10.