Microsoft has assigned CVE-2026-45585 and shipped mitigation guidance for YellowKey, a Windows BitLocker bypass that anonymous researcher 'Nightmare Eclipse' disclosed last week with a working PoC. The attack places crafted FsTx files on a USB drive or EFI partition, reboots into WinRE, and holds CTRL during boot to drop into a shell with full access to BitLocker-protected drives. Microsoft says no patch is available yet. Mitigations include removing the autofstx.exe entry from Session Manager's BootExecute and reconfiguring BitLocker to require TPM+PIN at startup. Nightmare Eclipse is the same researcher who recently dropped BlueHammer, RedSun, GreenPlasma, UnDefend, and MiniPlasma.
A researcher who goes by Chaotic Eclipse has dropped working proof-of-concept code on GitHub for a Windows local privilege escalation that gives SYSTEM access on fully patched Windows 11 Pro and Windows Server 2025. The bug lives in the Cloud Filter driver cldflt.sys and is, the researcher says, the same flaw Google Project Zero reported to Microsoft as CVE-2020-17103 in 2020, which Microsoft said it fixed in December 2020. The original Google PoC works unmodified. May 2026 Patch Tuesday updates do not stop it. The same researcher has dropped several other Windows zero-days in recent weeks, all of which were quickly seen in real attacks.
The Pwn2Own Berlin 2026 contest wrapped up Saturday at OffensiveCon, paying out $1,298,250 for 47 unique zero-days across three days. Taiwan's DEVCORE took the Master of Pwn title with 50.5 points and $505,000 in winnings. The headline Day 3 result came from DEVCORE researcher splitline, who chained two bugs into a successful exploit of Microsoft SharePoint, earning $100,000 and 10 points. SharePoint had survived a failed Rapid7 attempt on Day 2, making this a notable late-contest catch. Day 3 also saw attempts against VMware ESXi, Windows 11, Red Hat Enterprise Linux, and OpenAI Codex. All disclosed bugs now enter ZDI's 90-day disclosure window.
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.
The second day of Pwn2Own Berlin 2026 added $385,750 across 15 unique zero-days, bringing the running total to $908,750 across 39 zero-days. The headline was Orange Tsai of DEVCORE chaining three bugs to gain SYSTEM-level remote code execution on Microsoft Exchange Server, taking the $200,000 top prize and pushing his event total past $375,000. Other day-two wins included a Windows 11 integer-overflow LPE, a Red Hat Enterprise Linux for Workstations root, a use-after-free in NVIDIA Container Toolkit, and AI-category exploits against LM Studio, Cursor, OpenAI Codex, and Anthropic Claude Desktop (the last as a collision with a previously known bug).
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.
Day one of the Pwn2Own Berlin 2026 hacking contest at OffensiveCon paid out 523,000 dollars across 24 unique zero-days, with Trend Micro's Zero Day Initiative reporting wins against fully patched Microsoft Edge, Windows 11, Red Hat Enterprise Linux for Workstations, NVIDIA Container Toolkit and Megatron Bridge, OpenAI Codex, and LiteLLM. Orange Tsai's four-bug logic chain that escaped the Edge sandbox took the biggest single prize at 175,000 dollars. An Anthropic Claude Code entry was ruled a collision (the bug was already known to the vendor). Each affected vendor now has 90 days to ship a fix before ZDI publishes technical details.
A researcher who calls themselves Chaotic Eclipse - and who has weaponized every prior Windows flaw they have leaked this year - dropped working proof-of-concept code for two unpatched zero-days on May 12. YellowKey lets anyone with physical access to a Windows 11 or Server 2022/2025 machine plug in a USB stick, hold CTRL during a reboot into the Windows Recovery Environment, and get a shell with full access to the BitLocker-protected drive. GreenPlasma is a privilege escalation against the CTFMON service that hands an unprivileged user a path to SYSTEM. Independent researchers including Will Dormann and Kevin Beaumont have confirmed that YellowKey works as advertised.
Google's Threat Intelligence Group says it caught the first known case of a real attacker using a large language model to find and weaponize a zero-day - a 2FA bypass in a popular but unnamed open-source web-based system administration tool. Google has high confidence the Python exploit was AI-generated, citing textbook code structure, abundant educational docstrings, and a hallucinated CVSS score in the script. The flaw was a high-level logic bug, the kind LLMs excel at spotting, rather than a memory corruption issue. Google rules out Gemini and warns that AI-assisted exploit development is being industrialized via account-pooling and proxy relays for premium models.
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.
TrustStrike Labs