CVE-2026-6621

1024bit extend-deep index.js prototype pollution

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.

Affected

1024bit · extend-deep

CVSS v4.0 VULDB

5.5 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 VULDB

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

CVSS v2.0 VULDB

7.5 HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS

0.56% chance of exploitation in the next 30 days, 45th percentile

Published

2026-04-20

Proof-of-concept exploits (1)

• sudo-secure/security-research/blob/main/extend-deep/prototype-pollution/PoC.md1★ · 2026-04-23

References

• CVE Record
• NVD entry

Related

• CVE-2026-5472
• CVE-2026-6486
• CVE-2026-6492
• CVE-2026-6594