Seamonkey was updated to 2.53.10.2:

* Obtain Windows code-signing certificate for SeaMonkey binary and
  update signing bug 1438084.
* Support SHA-2 hashes in CertIDs in OCSP responses - port of bug
  1746221.
* Fix rust 1.57 Windows linking for SeaMonkey 2.53 bug 1746785.
* SeaMonkey 2.53.10.2 uses the same backend as Firefox and contains
  the relevant Firefox 60.8 security fixes.
* Additional important security fixes up to Current Firefox 91.4.1
  ESR and a few enhancements have been backported. We will continue
  to enhance SeaMonkey security in subsequent 2.53.x beta and
  release versions as fast as we are able to.
* SeaMonkey 2.53.10.2 shares most parts of the mail and news code
  with Thunderbird. Please read the Thunderbird 60.0 release notes
  for specific changes and security fixes in this release.