What is CVE-2020-17131?

CVE-2020-17131 is a medium-severity vulnerability in Microsoft Chakracore, classified under Out-of-bounds Write. CVSS score: 4.2/10. Published 2020-12-10.

How severe is CVE-2020-17131?

Medium severity. CVSS v3 base score is 4.2 out of 10.

Is CVE-2020-17131 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Microsoft Chakracore

CVE-2020-17131

Chakra Scripting Engine Memory Corruption Vulnerability

Vulnerability class: Buffer Overflow

Published 2020-12-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.020 (81.1th percentile), scored 2026-10-28.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.020 · change: +0.002

Affected products

Microsoft Chakracore — versions 0
Microsoft Edge
Microsoft Edge (Edgehtml-Based) — versions 1.0..0
Microsoft Windows 10 — versions 20h2, 1809, 1903
Microsoft Windows Server 2019

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

ARPSyndicate/cve-scores

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2020-17131 (vendor-advisory, patch)
af854a3a-2127-422b-91ae-364da2661108 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2020-17131?: CVE-2020-17131 is a medium-severity vulnerability in Microsoft Chakracore, classified under Out-of-bounds Write. CVSS score: 4.2/10. Published 2020-12-10.
How severe is CVE-2020-17131?: Medium severity. CVSS v3 base score is 4.2 out of 10.
Is CVE-2020-17131 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.