The 200th curl release found 3 major security advisories from the curl bug-bounty program. These are the advisories:
This is a Use-After-Free in the OpenSSL backend code that in the absolutely worst case can lead to an RCE, a Remote Code Execution. The flaw is reasonably recently added and it’s very hard to exploit but you should upgrade or patch immediately.
The issue occurs when TLS session related info is sent from the TLS server when the transfer that previously used it is already done and gone.
When libcurl accepts custom TELNET options to send to the server, it the input parser was flawed which could be exploited to have libcurl instead send contents from the stack.
In the Schannel backend code, the selected cipher for a transfer done with was stored in a static variable. This caused one transfer’s choice to weaken the choice for a single set transfer could unknowingly affect other connections to a lower security grade than intended.