tl;dr: CVE-2015-1793 does not appear to affect Tor. Update your OpenSSL anyway; other applications are certainly affected. Hi, all! Here's the announcement for today's major security issue in OpenSSL1.0.2c, 1.0.2b, 1.0.1n and 1.0.1o: https://www.openssl.org/news/secadv_20150709.txt So far, I have only looked at the announcement itself, and the commit messages--not yet the code. But from what I can tell, it should only affect programs that have trusted certificates in their store. Tor itself does not use trusted root certificates, so it is not affected. (Similarly, TorBrowser should not be affected: it uses NSS, not OpenSSL.) Still, you likely have lots of other programs that depend on OpenSSL and trusted certificates to build certificate chains, and those programs _will_ be affected. So, you should probably upgrade OpenSSL as soon as feasible. (I'll spend a little more time patches and reviewing Tor's code to confirm my analysis above, and I invite others to do so as well. I'm in recovery from my vacation today.) best wishes, -- Nick