"Researcher Max Justicz discovered a potential RCE and other
vulnerabilities in the Fossil distributed version control system.
(https://fossil-scm.org/)  Patches to address these issues are now
available for download.  Package maintainers who bundle Fossil are
encouraged to update their packages without unnecessary delay.

All vulnerabilities require a pre-existing trust relationship between
the victim and the attacker.  In other words, the attacker must be
either a site administrator, or someone with check-in privileges on
the project.  There are no known vulnerabilities to servers from web
users entering tickets or forum messages or wiki or doing other
on-line operations.  The attacks require the ability to push, at
least, and the most serious RCE problem requires the ability to
configure a server in malicious ways.  If you are unable to upgrade to
one of the patched versions of Fossil, then you are encouraged at
least to know well the people from whom you clone or pull.

Precompiled binaries and source tarballs for the patched versions of
Fossil are available on the Fossil download page
(http://fossil-scm.org/fossil/uv/download.html).  However, the dozens
of check-ins that went into generating these patches, and the tickets
that describe the specifics of the vulnerabilities, will be embargoed
for a few days.

See the thread on the Fossil Forum
(https://fossil-scm.org/forum/info/a05ae3ce7760daf6) for follow up
information or to communicate directly with the Fossil developers."