A gthumb security update has been released for Debian GNU/Linux 8 LTS

Package : gthumb
Version : 3:3.3.1-2.1+deb8u2
CVE ID : CVE-2019-20326

A heap-based buffer overflow in
_cairo_image_surface_create_from_jpeg() in
extensions/cairo_io/cairo-image-surface-jpeg.c in gThumb and Pix
allows attackers to cause a crash and potentially execute arbitrary
code via a crafted JPEG file.

For Debian 8 "Jessie", this problem has been fixed in version
3:3.3.1-2.1+deb8u2.

We recommend that you upgrade your gthumb packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS