A week in security (January 26 – February 1)

Last week on Malwarebytes Labs: Match, Hinge, OkCupid, and Panera Bread breached by ransomware group TikTok’s privacy update mentions immigration status. Here’s why. Meta confirms it’s working on premium subscription for its apps Microsoft Office zero-day lets malicious documents slip past securi...

PT-2026-6803

Name of the Vulnerable Software and Affected Versions BeyondTrust Remote Support versions prior to 25.3.2 BeyondTrust Privileged Remote Access versions prior to 25.1.1 Description A pre-authentication operating system command injection flaw exists in BeyondTrust Remote Support and Privileged Remo...

Critical Ivanti Endpoint Manager Mobile (EPMM) zero-day exploited in the wild (CVE-2026-1281 & CVE-2026-1340)

Overview On January 29, 2026, Ivanti disclosed two new critical vulnerabilities affecting Endpoint Manager Mobile EPMM: CVE-2026-1281 and CVE-2026-1340. The vendor has indicated that exploitation in the wild has already occurred prior to disclosure. This has been echoed by CISA who added...

CVE-2026-0797

creationtimestamp| type| source ---|---|--- 2026-01-30 05:00:00+00:00| seen| http://www.zerodayinitiative.com/advisories/ZDI-26-050/ 2026-02-21 00:17:57+00:00| seen| https://bsky.app/profile/thehackerwire.bsky.social/post/3mfddw4ydps2c 2026-02-21 00:20:44+00:00| seen|...

Two Ivanti EPMM Zero-Day RCE Flaws Actively Exploited, Security Updates Released

Ivanti has rolled out security updates to address two security flaws impacting Ivanti Endpoint Manager Mobile EPMM that have been exploited in zero-day attacks, one of which has been added by the U.S. Cybersecurity and Infrastructure Security Agency CISA to its Known Exploited Vulnerabilities KEV...

Microsoft Office zero-day lets malicious documents slip past security checks

Microsoft issued an emergency patch for a high-severity zero-day vulnerability in Office that allows attackers to bypass document security checks and is being exploited in the wild via malicious files. Microsoft pushed the emergency patch for the zero‑day, tracked as CVE-2026-21509, and classifie...

Microsoft releases update to address zero-day vulnerability in Microsoft Office

Microsoft has published three out-of-band OOB updates so far in January 2026. One of these updates was released to address a vulnerability, CVE-2026-21509, affecting Microsoft Office that has been reportedly exploited in the wild. Additional OOB updates have been published to resolve operational...

“The bugs pick you”: Inside Wouter’s security research journey

If you ask Wouter when his security journey began, he’ll take you back to a childhood in the Netherlands, tinkering with the 8086 PC his parents brought home when he was five or six. That early curiosity, fueled by racing games, trial-and-error exploration, and a tendency to pull things apart jus...

Patch Tuesday and the Enduring Challenge of Windows’ Backwards Compatibility

Introduction If you received an email with the subject “I LOVE YOU” and an attachment called “LOVE-LETTER-FOR-YOU.TXT”, would you open it? Probably not, but back in the year 2000, plenty of people did exactly that. The internet learned a hard lesson about the disproportionate power available to a...

Google Warns of Active Exploitation of WinRAR Vulnerability CVE-2025-8088

Google on Tuesday revealed that multiple threat actors, including nation-state adversaries and financially motivated groups, are exploiting a now-patched critical security flaw in RARLAB WinRAR to establish initial access and deploy a diverse array of payloads. "Discovered and patched in July 202...

CVE-2025-29867

creationtimestamp| type| source ---|---|--- 2026-01-28 05:00:00+00:00| seen| http://www.zerodayinitiative.com/advisories/ZDI-26-047/...

PT-2026-5123

Microsoft has issued an emergency patch for a zero-day vulnerability CVE-2021-21509 in Office, allowing attackers to bypass OLE mitigations and execute malware. CISA has included the flaw in their KEV catalog. Microsoft Office SecurityPatch ZeroDayVulnerability https://t.co/WMeToNOuIK...

ZeroDay vulnerability fixed in Microsoft Office

Microsoft has fixed a ZeroDay vulnerability in Microsoft Office. The vulnerability is in the way Microsoft Office handles untrusted input, which allows attackers to bypass security features locally. This can affect the integrity of security decisions made by the software. The reliance on untruste...

Pwn2Own: Researchers Earn $1 Million for 76 Zero-Days

Discover how TrendAI Zero Day Initiative ZDI identified critical vulnerabilities across connected vehicles, EV chargers, and automotive systems...

Toward Risk Thresholds for AI-Enabled Cyber Threats: Enhancing Decision-Making under Uncertainty with Bayesian Networks

Artificial intelligence AI is increasingly being used to augment and automate cyber operations, altering the scale, speed, and accessibility of malicious activity. These shifts raise urgent questions about when AI systems introduce unacceptable or intolerable cyber risk, and how risk thresholds...

Cisco Fixes Actively Exploited Zero-Day CVE-2026-20045 in Unified CM and Webex

Cisco has released fresh patches to address what it described as a "critical" security vulnerability impacting multiple Unified Communications CM products and Webex Calling Dedicated Instance that it has been actively exploited as a zero-day in the wild. The vulnerability, CVE-2026-20045 CVSS...

openSUSE 16 Security Update : gimp (openSUSE-SU-2026:20055-1)

The remote openSUSE 16 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:20055-1 advisory. Changes in gimp: Update to 3.0.6: - Security: - During development, we received reports from the Zero Day Initiative of potential security issue...

China-Linked APT Exploited Sitecore Zero-Day in Critical Infrastructure Intrusion

A threat actor likely aligned with China has been observed targeting critical infrastructure sectors in North America since at least last year. Cisco Talos, which is tracking the activity under the name UAT-8837 , assessed it to be a China-nexus advanced persistent threat APT actor with medium...

Exploit for Deserialization of Untrusted Data in Microsoft

CVE-2025-53770 Security Advisory Microsoft SharePoint Serv...

Cisco Patches Zero-Day RCE Exploited by China-Linked APT in Secure Email Gateways

Cisco on Thursday released security updates for a maximum-severity security flaw impacting Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager, nearly a month after the company disclosed that it had been exploited as a zero-day by a China-nexus advanced...