This is a security release fixing two issues. The first one performs extra sanitization for some edge cases in the Git Smart Protocol which can lead to attempting to parse outside of the buffer.
The second fix affects the certificate check callback. It provides a valid parameter to indicate whether the native cryptographic library considered the certificate to be correct. This parameter is always 1/true before this fix leading to a possible MITM.
This does not affect you if you do not use the custom certificate callback or if you do not take this value into account.
A list of commits since the last release follows
82d621c Merge pull request #1402 from libgit2/ethomson/0_23_1 097036d Update change log for 0.23.1 7f259c8 Update version number to 0.23.1 595938e Update LibGit2Sharp.NativeBinaries to 1.0.164