Apple has released OS X version 10.10.5, and with it comes a bevy of fixes. Although the company states that this update "improves the stability, compatibility, and security of your Mac," the star of the show here may be a fix for the DYLD_PRINT_TO_FILE privilege escalation vulnerability. That bug was discovered by Stefan Esser, and it's apparently under attack in the wild. Esser had previously published an OS X kernel extension called SUIDGuard that users could install to mitigate the problem.
The story would end there, but there's one more thing. Esser has since tweeted that Apple "fixed some bugs and made another security problem worse" in 10.10.5. Another tweet recommends that users leave SUIDGard installed if they're running the updated version of OS X, which may allude to another, as-yet unpatched vulnerability.
For more details about the security vulnerabilities fixed in this update, check out Apple's patch notes.