9.8

CVE-2023-23557: facebook hermes Type Confusion

CVSS: 9.8v3.1CriticalModified
Published 18-05-2023Last modified 21-01-2025
Open JSON

Vulnerability summary

CVE-2023-23557 is a critical (CVSS 9.8) Type Confusion vulnerability in facebook hermes. EPSS estimates a 0.89% chance of exploitation in the next 30 days, higher than 58.7% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.89%
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. 18-05-2023
    PublishedVulnerability first disclosed.
  2. 21-01-2025
    Last modifiedVulnerability information updated.

Description

An error in Hermes' algorithm for copying objects properties prior to commit a00d237346894c6067a594983be6634f4168c9ad could be used by a malicious attacker to execute arbitrary code via type confusion. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.89%

Chance of exploitation in the next 30 days

Percentile

59%

Versus all other CVEs

30-day change

0.00 pp

From 0.89% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.89%

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
  • hermes< a00d237346894c6067a594983be6634f4168c9ad | < 2023-01-10

1 vendor · 1 product

References

2 links