PT-2026-7397 · Microsoft · Outlook+2

Published 2026-02-10 · Updated 2026-02-25 · CVE-2026-21511

Positive Technologies (AI Summary)

CVSS v2.0

7.8

High

Base vector

AV:N/AC:L/Au:N/C:C/I:N/A:N

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

Description The software contains a flaw related to data spoofing. This issue allows an unauthorized attacker to perform spoofing over a network through deserialization of untrusted data. The vulnerability enables attackers to affect the system.

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

Deserialization of Untrusted Data

Weakness Enumeration

CWE-502

Related Identifiers

BDU:2026-01744

CVE-2026-21511

Affected Products

Outlook

Office Word

Sharepoint Server

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2026-21511 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21511 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-21511 · Security Note
• https://osv.dev/vulnerability/CVE-2026-21511 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-01744 · Security Note
• https://t.me/avleonovcom/1631 · Telegram Post
• https://twitter.com/Mahendrak29/status/2021490658448638359 · Twitter Post
• https://twitter.com/Mahendrak29/status/2021410046371045533 · Twitter Post
• https://twitter.com/StamusN/status/2026691222727700948 · Twitter Post