PT-2026-40256 · Microsoft · Office

Published 2026-05-12 · Updated 2026-05-18 · CVE-2026-42831

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Microsoft Office (affected versions not specified)

Description A heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally. A heap-based buffer overflow occurs when an application writes more data to a heap-allocated memory block than it can hold, potentially corrupting adjacent memory.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

RCE

Heap Based Buffer Overflow

Weakness Enumeration

CWE-122

Related Identifiers

BDU:2026-06757

CVE-2026-42831

Affected Products

Office

References · 6

• https://bdu.fstec.ru/vul/2026-06757 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42831 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-42831 · Security Note
• https://t.me/CVEtracker/53522 · Telegram Post
• https://twitter.com/cybrsecpath/status/2056222043637768656 · Twitter Post
• https://t.me/cveNotify/163717 · Telegram Post