Several security issues have been found in the Mozilla Firefox web browser: Multiple memory safety errors and other implementation errors may lead to the execution of arbitrary code, denial of service or information disclosure.
For the oldstable distribution (jessie), these problems have been fixed in version 52.7.1esr-1~deb8u1.
For the stable distribution (stretch), these problems have been fixed in version 52.7.1esr-1~deb9u1.
We recommend that you upgrade your firefox-esr packages.
Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/