Found this link on another forum.
It appears that Otter (72) is vulnerable to this attack assuming that the test is correct.
Warning! Your web browser is vulnerable to Logjam and can be tricked into using weak encryption. You should update your browser.
https://weakdh.org/
Affects also Qutebrowser and Seamonkey, while DWB, Luakit and old Opera are unaffected. I have no idea how the test works or what it even tests.
Background information for those interested:
http://blog.cryptographyengineering.com/2015/05/attack-of-week-logjam.html (english)
http://www.heise.de/security/meldung/Logjam-Attacke-Verschluesselung-von-zehntausenden-Servern-gefaehrdet-2657502.html (deutsch)
I've disabled affected ciphers in default set:
https://github.com/OtterBrowser/otter-browser/commit/f06de364bb724c573ca52fb8cd6554207183b3a8
I dont think he has the attack values set yet?
He said he has and that's why using current otter versions on https://weakdh.org/ will tell you "Good News! Your browser is safe against the Logjam attack." .