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CVE-2020-7770Prototype Pollution
- 6.5MediumCVSS base score
- 1.9%Exploitation in 30 daysEPSS · top 20% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
This affects the package json8 before 1.0.3. The function adds in the target object the property specified in the path, however it does not properly check the key being set, leading to a prototype pollution.
Timeline
ID reserved
By snyk
- 10 months later
· 10 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| snykCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.9% · top 20% of all CVEs (13 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
json8
- affected unspecified – < 1.0.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
References
References2
- https://snyk.io/vuln/SNYK-JS-JSON8-1017116 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/sonnyp/JSON8/commit/2e890261b66cbc54ae01d0c79c71b0fd18379e7e (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-0999 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-7h43-gx24-p529 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-7770)Record last updated .