CVE-2026-42831 | Microsoft Office Remote Code Execution Vulnerability

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

Published: 2026-05-12 Last update: 2026-05-19 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42831 is rated Low Risk (37.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42831

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 2026-05-13 — 0.06% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42831

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2026-42831

GitHub Security Advisory for CVE-2026-42831

GHSA-vvc2-cg8v-mmjx · Severity: high — Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code...

Affected software / configurations for CVE-2026-42831

Vendor Product Version Raw CPE
microsoft office < 16.0.19822.20190 cpe:2.3:a:microsoft:office:*:*:*:*:*:android:*:*
microsoft office 2024 cpe:2.3:a:microsoft:office:2024:*:*:*:ltsc:macos:*:*
microsoft office_long_term_servicing_channel 2021 cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:macos:*:*

References for CVE-2026-42831

cvelogic Threat Intelligence