xzgv and zgv are picture viewing utilities with a thumbnail based file selector.
Andrea Barisani of Gentoo Linux discovered xzgv and zgv allocate insufficient memory when rendering images with more than 3 output components, such as images using the YCCK or CMYK colour space. When xzgv or zgv attempt to render the image, data from the image overruns a heap allocated buffer.
An attacker may be able to construct a malicious image that executes arbitrary code with the permissions of the xzgv or zgv user when attempting to render the image.
There is no known workaround at this time.
All xzgv users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-gfx/xzgv-0.8-r2"
All zgv users should also upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-gfx/zgv-5.9"