CVE-2021-23426 json
Prototype Pollution
published 5y ago modified 4mo ago also GHSA-58g2-9fqr-36q2 , EUVD-2021-1982
- cvss
- 5.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 58%
- public exploits
- 0
- none known
Summary
This affects all versions of package Proto. It is possible to inject pollute the object property of an application using Proto by leveraging the merge function.
Is CVE-2021-23426 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.86% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- snyk.io https://snyk.io/vuln/SNYK-JS-PROTO-1316301 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/RL:U/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 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | Proto | <=1.1.4 |
no fix listed |
Affected products
- n/a Proto
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
-
snyk.io
/vuln/SNYK-JS-PROTO-1316301
web, exploit, mitigation, third-party-advisory
-
npmjs.com
/package/Proto
web, product, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-23426
advisory
-
github.com
/adriancmiranda/Proto
package
Sources
- CVE List CVE-2021-23426
- GitHub Advisory GHSA-58g2-9fqr-36q2
- NVD CVE-2021-23426
Fencer Intel 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.