An integer conversion error in Hermes bytecode generation, prior to commit 6aa825e480d48127b480b08d13adf70033237097, could have been used to perform Out-Of-Bounds operations and subsequently execute arbitrary code. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.
Conclusion & alert: CVE-2022-40138 is rated Moderate Risk (58/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.89%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 1.22% | 0.89% | -0.33% |
| 2 | 2025-10-20 | 0.79% | 1.22% | +0.43% |
| 3 | 2025-10-13 | — | 0.79% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
critical | CVE-2022-40138: 1 source package rows (hermes); 10 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.22-community, 3.23-community, edge-community); fixed 0, open 10. | https://security.alpinelinux.org/vuln/CVE-2022-40138 |
| URL | Tags |
|---|---|
| https://github.com/facebook/hermes/commit/6aa825e480d48127b480b08d13adf70033237097 | Patch Third Party Advisory |
| https://www.facebook.com/security/advisories/CVE-2022-40138 | Vendor Advisory |