Microsoft has rolled out fixes for two Defender vulnerabilities that have been exploited in zero-day attacks. CVE-2026-41091 is a link-following local privilege escalation in Microsoft Malware Protection Engine 1.1.26030.3008 and earlier that lets attackers gain SYSTEM. CVE-2026-45498 affects Defender Antimalware Platform 4.18.26030.3011 and earlier and triggers denial-of-service. Updates land automatically in Malware Protection Engine 1.1.26040.8 and Antimalware Platform 4.18.26040.7. CISA has added both to its KEV catalog and ordered FCEB agencies to patch within two weeks, by June 3. The same KEV update also added five legacy 2008-2010 Internet Explorer, DirectX, Acrobat, and Windows bugs that CISA suggests are seeing fresh exploitation.
ReliaQuest has documented active in-the-wild exploitation of CVE-2024-12802, a SonicWall Gen6 SSL-VPN MFA bypass that hits Gen6 devices even after they apply the firmware patch. SonicWall's advisory makes clear that on Gen6 hardware, the firmware update alone does not fix it - administrators must also delete the LDAP configuration that uses userPrincipalName, remove cached LDAP users, drop the SSL VPN User Domain back to LocalDomain, reboot, and rebuild the LDAP config without userPrincipalName. Gen7 and Gen8 devices are patched by firmware alone. Intrusions observed between February and March 2026 looked like ransomware initial-access broker activity with 30-60 minute Cobalt Strike and BYOVD attempts.
The 18-year-old heap overflow in NGINX's rewrite module, CVE-2026-42945, disclosed last week as part of the 'Rift' bug cluster, is now seeing real exploitation attempts. AI-native security firm VulnCheck says its honeypot networks have caught attackers probing the flaw, though the goal of the campaigns is not yet clear. The vulnerability lets an unauthenticated attacker crash NGINX worker processes by sending crafted HTTP requests. Turning that crash into remote code execution requires the target host to have Address Space Layout Randomization (ASLR) disabled, which is uncommon by default, but the worker-crash denial-of-service is exploitable on its own and rated urgent.
VulnCheck says attackers are chaining three critical bugs (CVE-2026-28515, CVE-2026-28517, CVE-2026-28516) in openDCIM, an open-source data center management web app, to drop PHP web shells on exposed installs. All three rate CVSS 9.3 and cover missing authorization, OS command injection, and SQL injection. They can be combined over five HTTP requests to land a reverse shell. The activity comes from a single Chinese IP using what VulnCheck describes as a customized version of Vulnhuntr, a public AI-driven vulnerability discovery tool. The campaign is one of the first publicly documented cases of an open-source AI vuln scanner being repurposed for real-world exploitation.
Just two days after a 138-fix Patch Tuesday that listed no zero-days, Microsoft disclosed CVE-2026-42897, an Exchange Server XSS-to-spoofing flaw it has tagged 'Exploitation Detected.' The bug is rated CVSS 8.1 and reported by an anonymous researcher. An unauthenticated attacker emails a crafted message; if the victim opens it in Outlook Web Access and meets certain interaction conditions, arbitrary JavaScript runs in the browser session context, enabling spoofing and session abuse. On-prem Exchange Server 2016, 2019, and Subscription Edition are affected; Exchange Online is not. No permanent patch exists yet, only mitigation through the Exchange Emergency Mitigation Service.
Cisco disclosed and patched a second perfect-score authentication bypass in its Catalyst SD-WAN Controller and Manager (formerly vSmart and vManage). The bug, CVE-2026-20182 (CVSS 10.0), was found by Rapid7 while investigating the earlier CVE-2026-20127 wave, and lives in the same vdaemon service over DTLS port 12346. An unauthenticated attacker can become a trusted peer of the controller, log in as a privileged internal account, hit the NETCONF interface, and rewrite the entire SD-WAN fabric. Cisco Talos already attributes limited in-the-wild exploitation to UAT-8616, an actor with operational-relay-box ties that has been targeting Cisco SD-WAN since 2023.
QiAnXin XLab has tied the ongoing exploitation of cPanel's CVE-2026-41940 to a previously-quiet threat actor it tracks as Mr_Rot13, who has been operating since at least 2020. The attack chain exploits the cPanel and WHM authentication bypass to drop a Go-based infector that adds an attacker SSH key, plants a PHP web shell, and serves a fake login page to steal cPanel credentials (ROT13-encoded, exfiltrated to wrned[.]com). The final payload is a cross-platform backdoor called Filemanager that runs on Windows, macOS, and Linux. XLab counts over 2,000 attacker source IPs currently scanning for this flaw.
Ivanti disclosed Wednesday that attackers are exploiting a zero-day in Endpoint Manager Mobile (EPMM) to gain admin-level remote code execution on enterprise MDM servers. CVE-2026-6973. Successful exploitation gives the attacker control over the MDM platform that pushes apps and configurations to managed mobile fleets - a foothold that can pivot into managed devices and the corporate identity layer. CISA added the flaw to its Known Exploited Vulnerabilities catalog the same day with a federal patch deadline next week. Ivanti products have a long history of zero-day exploitation.
Palo Alto Networks confirmed Wednesday that attackers are exploiting a zero-day in its firewall login portal to run code as root on PA-Series and VM-Series firewalls. CVE-2026-0300 (CVSS 9.3) is a buffer overflow in the User-ID Authentication Portal (Captive Portal) that lets unauthenticated attackers send crafted packets and execute code without any login. Palo Alto Unit 42 attributed the activity to CL-STA-1132, a likely state-sponsored cluster that started probing on April 9 and achieved RCE a week later. Attackers deploy tunneling tools and enumerate Active Directory using the firewall's service account. First patches arrive May 13. Shadowserver counts 5,800+ exposed VM-Series firewalls.
LiteLLM, the popular open-source gateway used to centralize API access for OpenAI, Anthropic, and other AI providers, has a critical pre-authentication SQL injection bug that attackers started exploiting just 36 hours after the security advisory went public. The flaw lets anyone who can reach the proxy port read all the API keys stored inside - including master keys, virtual keys, and provider credentials. The bug was in the bearer-token check: the token was concatenated into a SQL query instead of passed as a parameter. Sysdig saw the first attack at 04:24 UTC on April 26, hitting three tables that hold the most valuable secrets.
TrustStrike Labs