Update RELEASE.md

RELEASE.md

@@ -1,6 +1,9 @@
 # Release 1.15.1
 
-<REPLACE THIS TEXT WITH THE RELEASE NOTES>
+## Bug Fixes and Other Changes
+* Fixes a security vulnerability where converting a Python string to a `tf.float16` value produces a segmentation fault
+* Updates `curl` to `7.66.0` to handle [CVE-2019-5482](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5482) and [CVE-2019-5481](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5481)
+* Updates `sqlite3` to `3.30.01` to handle [CVE-2019-19646](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19646), [CVE-2019-19645](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19645) and [CVE-2019-16168](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-16168)
 
 # Release 1.15.0
 This is the last 1.x release for TensorFlow. We do not expect to update the 1.x branch with features, although we will issue patch releases to fix vulnerabilities for at least one year.