Vulnerabilities

CVSS

7.8 High

Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

Risk score

100.0

Known exploited

CISA KEV

Published

2026-01-26

Status

Published

Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.

Weaknesses

CWE-807

Coverage 2

threat-intel

Gamaredon Exploits WinRAR to Deliver GammaWorm and GammaSteel Against Ukraine

The Gamaredon group is exploiting a WinRAR vulnerability (CVE-2025-8088) to deploy a multi-stage malware campaign targeting Ukraine. This campaign utilizes GammaWorm and GammaSteel, designed for data theft and persistenc…

The Hacker News · Jun 2, 2026 High

CVE-2025-8088CVE-2026-21509RUUAwinrarmalwarevulnerability

threat-intel

Exploits and vulnerabilities in Q1 2026

This Securelist report analyzes vulnerability trends and exploitation activity during Q1 2026, focusing on the expansion of exploit kits targeting Microsoft Office, Windows, and Linux operating systems. The report highli…

Securelist · May 7, 2026 High

CVE-2018-0802CVE-2017-11882CVE-2017-0199USvulnerabilityexploitationrce

All articles mentioning it

Advisories and references

• msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509
• cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-...
• vicarius.io/vsociety/posts/cve-2026-21509-detection-script-microsoft...
• vicarius.io/vsociety/posts/cve-2026-21509-mitigation-script-microsof...