libjpeg-turbo is a MMX, SSE, and SSE2 SIMD accelerated JPEG library
libjpeg-turbo does not check for certain duplications of component data during the reading of segments that follow Start Of Scan (SOS) JPEG markers.
Remote attackers could obtain sensitive information from uninitialized memory locations via a crafted JPEG images.
There is no known workaround at this time.
All libjpeg-turbo users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libjpeg-turbo-1.4.2"