CVE-2020-7770 json
Prototype Pollution
published 2020-11-12 5 y ago modified 2026-07-08 4 mo ago also GHSA-7h43-gx24-p529 , EUVD-2021-0999
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.9%
- EPSS 1.9% chance of exploitation in 30 days, percentile 79%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Exploit prediction
1.89% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- snyk.io https://snyk.io/vuln/SNYK-JS-JSON8-1017116 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| 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 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | json8 | <1.0.3 |
1.0.3 |
Affected products
- n/a json8
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
-
github.com
/sonnyp/JSON8/commit/2e890261b66cbc54ae01d0c79c71b0fd18379e7e
web, patch, third-party-advisory
-
snyk.io
/vuln/SNYK-JS-JSON8-1017116
web, exploit, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2020-7770
advisory
-
npmjs.com
/package/json8
web
Sources
- CVE List CVE-2020-7770
- GitHub Advisory GHSA-7h43-gx24-p529
- NVD CVE-2020-7770
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