How severe is CVE-2022-40138?

CVE-2022-40138 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2022-40138 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-40138?

CVE-2022-40138 affects Facebook Hermes. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2022-40138?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2022-40138 published?

CVE-2022-40138 was published on 2022-10-11 and last updated on 2026-06-17.

CVE-2022-40138

CVE-2022-40138 is a critical-severity vulnerability in Facebook Hermes with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-681.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-681
Affected product: Facebook Hermes
Published: 2022-10-11
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2022-40138?: 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.
How severe is CVE-2022-40138?: CVE-2022-40138 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2022-40138 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-40138?: CVE-2022-40138 affects Facebook Hermes. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2022-40138?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2022-40138 published?: CVE-2022-40138 was published on 2022-10-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:facebook:hermes:*:*:*:*:*:*:*:*

More vulnerabilities in Facebook Hermes

CVE-2023-30470 — Critical (CVSS 9.8): A use-after-free related to unsound inference in the bytecode generation when optimizations are enabled for Hermes…
CVE-2023-28081 — Critical (CVSS 9.8): A bytecode optimization bug in Hermes prior to commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 could be used to cause…
CVE-2023-25933 — Critical (CVSS 9.8): A type confusion bug in TypedArray prior to commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 could have been used by a…
CVE-2023-23557 — Critical (CVSS 9.8): An error in Hermes' algorithm for copying objects properties prior to commit a00d237346894c6067a594983be6634f4168c9ad…
CVE-2023-23556 — Critical (CVSS 9.8): An error in BigInt conversion to Number in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have…
CVE-2022-35289 — Critical (CVSS 9.8): A write-what-where condition in hermes caused by an integer overflow, prior to commit…

All CVEs affecting Facebook Hermes →

Other CWE-681 vulnerabilities

CVE-2021-36357 — Critical (CVSS 9.8): An issue was discovered in OpenPOWER 2.6 firmware. unpack_timestamp() calls le32_to_cpu() for endian conversion of a…
CVE-2021-38187 — Critical (CVSS 9.8): An issue was discovered in the anymap crate through 0.12.1 for Rust. It violates soundness via conversion of a *u8 to a…
CVE-2019-19317 — Critical (CVSS 9.8): lookupName in resolve.c in SQLite 3.30.1 omits bits from the colUsed bitmask in the case of a generated column, which…
CVE-2019-14842 — Critical (CVSS 9.8): Structured reply is a feature of the newstyle NBD protocol allowing the server to send a reply in chunks. A bounds…
CVE-2018-8786 — Critical (CVSS 9.8): FreeRDP prior to version 2.0.0-rc4 contains an Integer Truncation that leads to a Heap-Based Buffer Overflow in…
CVE-2016-3074 — Critical (CVSS 9.8): Integer signedness error in GD Graphics Library 2.1.1 (aka libgd or libgd2) allows remote attackers to cause a denial…

Browse all CWE-681 vulnerabilities →