Merge pull request from GHSA-686w-5m7m-54vc

decNumberToString calls for a buffer that can hold a string of digits+14
characters, not a buffer of size digits+14.
We need to allocate an extra byte for the NUL byte.

-10E-1000010001, for example, will be stringified as -1.0E-1000010000
and decNumberToString will currently write an extra NUL byte after the
allocated buffer in the heap.

Originally reported by @SEU-SSL on GitHub.

Ref: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=64574

Fixes GHSA-686w-5m7m-54vc

NEWS.md

@@ -2,7 +2,7 @@
 
 ## Security
 
-- CVE-2023-50246: ....
+- CVE-2023-50246: Fix heap buffer overflow in jvp\_literal\_number\_literal
 - CVE-2023-50268: fix stack-buffer-overflow if comparing nan with payload
 
 ## CLI changes