Prototype Pollution

published 2021-11-03 5 y ago modified 2026-07-08 4 mo ago also GHSA-6g47-63mv-qpgh , EUVD-2021-2306

cvss: 5.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits: 0; none known

This affects the package dotty before 0.1.2. A type confusion vulnerability can lead to a bypass of CVE-2021-25912 when the user-provided keys used in the path parameter are arrays.

Patch / fix

fixed in 2 links 2

npm dotty 0.1.2
n/a dotty 0.1.2

github.com/deoxxa/dotty@88f6186 commit
snyk.io/vuln/SNYK-JS-DOTTY-1577292 advisory

Exploit prediction

1.28% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

snyk.io https://snyk.io/vuln/SNYK-JS-DOTTY-1577292 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.6	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RC:C
CNA	3.1	5.6	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub	3.1	5.6	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem	package	affected	fixed in
npm	dotty	<0.1.2	0.1.2

Affected products

n/a dotty

Classification

Weakness

CWE-843 Access of Resource Using Incompatible Type
CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

github.com /deoxxa/dotty/commit/88f61860dcc274a07a263c32cbe9d44c24ef02d7
web, patch, third-party-advisory
snyk.io /vuln/SNYK-JS-DOTTY-1577292
web, exploit, mitigation, patch, third-party-advisory, vdb-entry
nvd.nist.gov /vuln/detail/CVE-2021-23624
advisory
github.com /deoxxa/dotty
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary