Mozilla switched to mercurial in 2013 and certdata.txt no longer contains the CVS version number. CVS version 1.87 was equivalent to hg version 1.93. The upstream version number can now be found in the file nssckbi.h in the same directory - #define NSS_BUILTINS_LIBRARY_VERSION "1.94" ---- Upstream Sources - release branch: Full repository clone for latest release (~2GB): hg clone https://hg.mozilla.org/releases/mozilla-release mozilla/certdata.txt: https://hg.mozilla.org/releases/mozilla-release/raw-file/default/security/nss/lib/ckfw/builtins/certdata.txt mozilla/nssckbi.h: https://hg.mozilla.org/releases/mozilla-release/raw-file/default/security/nss/lib/ckfw/builtins/nssckbi.h ---- Upstream Sources - development branch (may not be released): Full repository clone for development tip: hg clone https://hg.mozilla.org/projects/nss mozilla/certdata.txt: https://hg.mozilla.org/projects/nss/raw-file/default/lib/ckfw/builtins/certdata.txt mozilla/nssckbi.h: https://hg.mozilla.org/projects/nss/raw-file/default/lib/ckfw/builtins/nssckbi.h