Vulnerability · Published Jan 29, 2026 · Assigned by GitHub_M

CVE-2026-25047deepHas vulnerable to Prototype Pollution via constructor.prototype

Critical 9.4

In plain English

A critical-severity prototype pollution in deepHas from sharpred. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 57% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)9.4Critical

Exploit odds (30 days)0.8%top 43.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack tooling1Public PoC

Official description

deepHas provides a test for the existence of a nested object key and optionally returns that key. A prototype pollution vulnerability exists in version 1.0.7 of the deephas npm package that allows an attacker to modify global object behavior. This issue was fixed in version 1.0.8.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	deephas	1.0.8	GHSA-2733-6c58-pf27

Affected products (as reported)

Vendor	Product	Versions
sharpred	deepHas	< 1.0.7

Weakness: CWE-1321 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References

https://github.com/sharpred/deepHas/security/advisories/GHSA-2733-6c58-pf27 x_refsource_CONFIRM
https://github.com/sharpred/deepHas/commit/8097fafd3776c613d8066546653e0d2c7b5fc465 x_refsource_MISC