What is CVE-2023-37139?

CVE-2023-37139 is a medium-severity vulnerability in Microsoft Chakracore, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2023-07-18.

How severe is CVE-2023-37139?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Microsoft Chakracore

CVE-2023-37139

ChakraCore branch master cbb9b was discovered to contain a stack overflow vulnerability via the function Js::ScopeSlots::IsDebuggerScopeSlotArray().

Vulnerability class: Buffer Overflow

Published 2023-07-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (57.2th percentile), scored 2026-10-08.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Microsoft Chakracore

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/chakra-core/ChakraCore/issues/6884 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2023-37139?: CVE-2023-37139 is a medium-severity vulnerability in Microsoft Chakracore, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2023-07-18.
How severe is CVE-2023-37139?: Medium severity. CVSS v3 base score is 5.5 out of 10.