CVE-2020-1911 json
Access of Resource Using Incompatible Type in Facebook Hermes
published 2020-09-04 6 y ago modified 2026-06-17 4 mo ago also GHSA-f5x2-xv93-4p23 , EUVD-2022-3700
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.0%
- EPSS 2.0% chance of exploitation in 30 days, percentile 80%
- public exploits
- 0
- none known
Summary
A type confusion vulnerability when resolving properties of JavaScript objects with specially-crafted prototype chains in Facebook Hermes prior to commit fe52854cdf6725c2eaa9e125995da76e6ceb27da allows attackers to potentially execute arbitrary code via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.
Patch / fix
Exploit prediction
2.00% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| 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 | 6.8 | AV:N/AC:M/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 | hermes-engine | <0.5.2 |
0.5.2 |
Affected products
- Facebook Hermes
Classification
- Weakness
-
- CWE-843 Access of Resource Using Incompatible Type
References
-
github.com
/facebook/hermes/commit/fe52854cdf6725c2eaa9e125995da76e6ceb27da
web, patch, third-party-advisory
-
facebook.com
/security/advisories/cve-2020-1911
web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2020-1911
advisory
Sources
- CVE List CVE-2020-1911
- GitHub Advisory GHSA-f5x2-xv93-4p23
- NVD CVE-2020-1911
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