SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-1896

A stack overflow vulnerability in Facebook Hermes 'builtin apply' prior to commit 86543ac47e59c522976b5632b8bf9a2a4583c7d2 (https://github.com/facebook/hermes/commit/86543ac47e59c522976b5632b8bf9a2a4583c7d2) allows attackers to potentially execute…

CRITICAL 9.8EPSS 2.42%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A stack overflow vulnerability in Facebook Hermes 'builtin apply' prior to commit 86543ac47e59c522976b5632b8bf9a2a4583c7d2 (https://github.com/facebook/hermes/commit/86543ac47e59c522976b5632b8bf9a2a4583c7d2) 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 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
2.42% probability · 84th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-121, CWE-787
Affected
facebook/hermes
Source
cve-assign@fb.com
EPSS trend
0%3%5%26 October 2026: 2.42%26 October 202626 October 2026

EPSS 2.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.