9.8

CVE-2020-1911: facebook hermes Type Confusion

CVSS: 9.8v3.1CriticalModified
AliasesGHSA-f5x2-xv93-4p23
Published 04-09-2020Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2020-1911 is a critical (CVSS 9.8) Type Confusion vulnerability in facebook hermes. EPSS estimates a 2.00% chance of exploitation in the next 30 days, higher than 80.5% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
2.00%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 04-09-2020
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

2.00%

Chance of exploitation in the next 30 days

Percentile

81%

Versus all other CVEs

30-day change

0.00 pp

From 2.00% on 20-09-2026

20-09-202620-10-2026
EPSS score
2.00%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Facebook1 product
  • hermescommit prior to fe52854cdf6725c2eaa9e125995da76e6ceb27da | < 0.4.3
Npm1 product
  • hermes-engine< 0.5.2

2 vendors · 2 products

References

3 links