Marcin Noga discovered multiple vulnerabilities in readxl, a GNU R package to read Excel files (via the integrated libxls library), which could result in the execution of arbitrary code if a malformed spreadsheet is processed.
For the stable distribution (stretch), these problems have been fixed in version 0.1.1-1+deb9u1.
We recommend that you upgrade your r-cran-readxl 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/