Deutsche Telekom's Red Team disclosed CVE-2026-41651, a local privilege escalation in the PackageKit daemon that has shipped in default Linux installations since November 2014. Any unprivileged local user can invoke 'pkcon install' without a polkit prompt, install or remove arbitrary packages, and escalate to root. CVSS 8.8. Confirmed-vulnerable defaults include Ubuntu Desktop and Server LTS, Debian Trixie, Rocky Linux 10.1, and Fedora 43; any RHEL server running Cockpit is also exposed because Cockpit loads PackageKit on demand via D-Bus. PackageKit 1.3.5 fixes it. The researchers credited Anthropic's Claude Opus with helping guide the discovery.
Just days after Microsoft patched BlueHammer (CVE-2026-33825) in Tuesday's Patch Tuesday, the same researcher 'Chaotic Eclipse' (aka Nightmare-Eclipse) has released a second Microsoft Defender local privilege escalation zero-day called RedSun. The exploit works on fully-patched Windows 10, Windows 11, and Windows Server systems with Windows Defender enabled, even after installing this week's April updates. The flaw abuses Defender's cloud file rollback behavior: when Defender detects a file with a 'cloud tag' it tries to restore it to its original location without validating the target path. The exploit uses NTFS junctions and opportunistic locks to redirect the write to C:\Windows\System32, overwriting system files like TieringEngineService.exe to gain SYSTEM privileges. Huntress Labs is reporting all three recently-leaked Windows Defender zero-days (BlueHammer, RedSun, and UnDefend) are now being exploited in the wild. The researcher has threatened to drop more severe RCE exploits in protest of how Microsoft handled their disclosure process. No patch available for RedSun yet. Working PoC code is public on GitHub.
A high-severity Docker Engine flaw allows attackers to bypass authorization plugins with a single oversized HTTP request. CVE-2026-34040 (CVSS 8.8) stems from an incomplete fix for CVE-2024-41110 from July 2024 - the original patch missed requests over 1MB, which get forwarded to the Docker daemon without their body, so the AuthZ plugin sees nothing to block while the daemon processes the full malicious payload. The result: a privileged container with root access to the host filesystem, exposing AWS credentials, SSH keys, Kubernetes configs, and everything else on the machine. Critically, Cyera researchers demonstrated that AI coding agents running inside Docker sandboxes can be tricked via prompt injection into crafting the bypass request themselves - no human attacker needed.
A frustrated security researcher published working exploit code for an unpatched Windows local privilege escalation flaw after Microsoft's Security Response Center mishandled the disclosure. The researcher, posting as Chaotic Eclipse, dropped the proof-of-concept on GitHub on April 3 with the message "I was not bluffing Microsoft." Will Dormann of Tharsos confirmed the exploit works - it combines a TOCTOU race condition with path confusion to access the SAM database containing local account password hashes, enabling escalation to SYSTEM privileges. The exploit is confirmed working on Windows desktop but unreliable on Windows Server. The researcher deliberately included bugs in the PoC, but the underlying technique is now public and weaponizable.
TrustStrike Labs