VirtualBox 4.3.26 (released 2015-03-16)

• GUI: in the snapshots pane, protect the age of snapshots against wrong host time (bug #13955)
  
• NAT Network: fixed a bug which prevented to propagate any DNS name server / domain / search string information to the NAT network (4.3.24 regression; bugs #13915, #13918)
  
• NAT Network: don´t delay the shutdown of VBoxSVC on Windows hosts
  
• Mouse support: the mouse could not be moved under rare conditions if no Guest Additions are installed (4.3.24 regression; bug #13935)
  
• Storage: if the guest ejects a virtual CD/DVD medium, make the change permanent (bugs #9858, #12885)
  
• VGA: made saving secondary screen sizes possible in X11 guests
  
• SDK: fixed the VirtualBox.tlb file (4.3.20 regression; bug #13943)
  
• rdesktop-vrdp: make it work with USB devices again (4.3.14 regression; bug #13901)
  
• USB: fixed a possible BSOD on Windows hosts under rare conditions
  
• iPXE: enable the HTTP download protocol on non-Linux hosts (bug #13628)
  
• Mac OS X hosts: don´t panic on hosts with activated SMAP (Broadwell and later; bug #13951)
  
• Linux hosts: don´t crash Linux 4.0 hosts (bug #13835)

VirtualBox 4.3.24 (released 2015-03-02)

• VMM: emulation fix for the ENTER instruction under certain conditions; fixes Solaris 10 guests (VT-x without unrestricted guest execution)
  
• VMM: fix for handling NMIs on Linux hosts with X2APIC enabled
  
• NAT/NAT Network: fix connection drops when the host´s DHCP lease was renewed (4.3.22 regression; Windows hosts only; bug #13839)
  
• NAT: don´t crash on an empty domain list when switching the DNS host configuration (4.3.22 regression; Mac OS X hosts only; bug #13874)
  
• PXE: re-enable it on Windows hosts (4.3.22 regression; Windows hosts only; bug #13842)
  
• Shared Folders: fixed a problem with Windows guests (4.3.22 regression; bug #13786)
  
• Audio: improved record quality when using the DirectSound audio backend
  
• VBoxManage: when executing the controlvm command take care that the corresponding VM runtime changes are saved permanently (bug #13892)
  
• Windows Installer: properly install the 32-bit version of VBoxRes.dll on 32-bit hosts (bug #13876)
  
• Linux hosts / guests: Linux 4.0 fixes (bug #13835)
  
• OS/2 Additions: fixed mouse integration (4.3.22 regression; bug #13825)
  
• X11 Additions: fixed a sporadic failure to deactivate virtual screens (bug #13845)

VirtualBox 4.3.22 (released 2015-02-12)

• VMM: refined measurement of TSC frequency on the host, improves timekeeping for guests
  
• VMM: decreased CPU load resulting from guest MMIO writes to the virtual APIC
  
• VMM: fixed interception of debug exceptions, observed while using the dbx debugger on Solaris guests (VT-x only)
  
• GUI: 3D overlay window positioning code improved, fixed potential misplacement of 3D accelerated guest graphics content
  
• GUI: fixed accident SSL authentication failures during update check on Windows hosts (bug #12969)
  
• GUI: never send the "ACPI power" keyboard scancode to the guest, we have the ACPI power button for that
  
• GUI: was unable to properly restore seamless mode VM from snapshot/saved-state under some circumstances
  
• VBoxHeadless: don´t crash if 3D is enabled in the VM settings (bug #10250)
  
• ATA: fixed several passthrough issues (bugs #12310, #1360)
  
• Audio: fixed DirectSound failure when the the host has no audio input device (Windows hosts only; bug #9205)
  
• SB16: fixed compatibility issue (bug #13769)
  
• Storage: fixed broken CD/DVD passthrough when using the IDE controller (bug #12310)
  
• NAT: new ping proxy for Windows hosts (bug #11871)
  
• NAT: Properly report outbound connect(2) failures to guest with TCP RST or ICMP (bug #10525)
  
• NAT Network: no need for frequent wakeups in VBoxNetDHCP and VBoxNetNAT (bug #11681)
  
• Host-only adapter: prevent Windows from creating an "Unidentified network" (bug #9688)
  
• Bridged Networking: don´t leak host-to-guest traffic to the wireless network when bridging to a wireless interface (bug #13714)
  
• Main: fixed a possible race when changing the medium leading to a deadlock under rare conditions (bug #13722)
  
• VBoxManage: fixed return code if starting a VM failed (bug #13773)
  
• Settings: on Windows host, do not use environment variable HOME at all, the settings location is derived from the user profile directory (bug #7689)
  
• API: fixed 2 deadlock opportunities related to medium handling (bugs #13789, #13801, thank you Alexander Urakov)
  
• API: fixed bug in XPCOM which created too few worker threads, sporadically resulting in a deadlock (bug #13802, thank you Alexander Urakov)
  
• SDK: fixed a garbage collection leak in the Python VirtualBox webservice API binding (bug #13817)
  
• Linux hosts: fixes for activated SMAP (Broadwell and later, bug #13820)
  
• X11 guests: prevent unwanted hiding of guest screens on multi-monitor guests (bug #13287)
  
• X11 guests: added support for X.Org Server 1.17
  
• X11 Additions: fixed a memory leak in VBoxService if libdbus is available but dbus-daemon isn´t running (bug #13770)
  
• Windows Additions: prevent VBox WDDM driver from loading if host reports weak OpenGL capabilities. 3D content now can be shown over Remote Desktop connection.
  
• Windows Additions: some fixes for recent Windows 10 Previews
  
• Linux Additions: fixed a compatibility issue with 64-bit Linux 2.4 kernels
  
• Linux Additions: fixed a potential use-after-free when unloading the VBoxGuest module
  
• Linux Additions: Linux 3.19 fixes (bug #13741)