This is a classic argument about security vulnerabilities: "Should we show everyone this vulnerability in this bit of software - then the bad guys will know how to use it!"
It may not surprise you that this discussion has been around since at least 1785 when Joseph Bramah, an inventor from Yorkshire, released a book called 'A Dissertation on the Construction of Locks' where he exposed the weaknesses of current (at the time) 'thief-proof locks'.
His central tenet was that thieves (and locksmiths) knew the weaknesses of locks anyway, whereas the general public (who were buying the locks) did not: his belief was that if the public was educated about such matters, they would be better able to protect themselves by bringing their knowledge up to the level of miscreants and professionals and thus be able to choose a better lock.
(It may also not surprise you that after exposing the weaknesses of another company's lock, he brought his own lock to market. To be fair to him though, he offered a prize of 200 guineas - around £27,000 GBP depending on assessment type - to the first person to pick the lock - which didn't happen for 67 years until an American Alfred Hobbs did so in 1851. It took him around 51 hours over 16 days).
I firmly believe that this has parallels in today's software heavy society: vulnerabilities should be openly discussed so that a general user may be made aware of any potential issues (that criminals and professionals are likely to know about anyway), and thus educated, can make better choices to protect themselves.
So, in a long winded way, to answer the question, "Do you think posting it here would really be the best course of action, for everybody else's security?" I believe that the answer is yes.
Just to note, I choose to interpret 'here' in an abstract way to mean, 'the internet', as well as stackexchange.