I recently noticed this old question which is an issue of contention among Shia and Sunnis.
We've got two versions of hadith of "the two weighty things" with one identifying the two with Quran and Ahl al-Bayt, and the other identifying the two with the Quran and the Sunnah.
But the 'sunnah' versions of the hadith as provided by this answer I suspected not to be reliable even in the first sight. First the hadith is not reported in any of the six sahih sources of the Sunni. And I also read the secondary sources provided are not reliable. Here I mention them one by one:
There is one mursal instance in Muwataa of Imam Malik. We know this Sunni Imam was a distant tabi'i and that his famous work has been subject to some doubts and controversy, and with the hadith not quoting any narrators, it is as good as null.
One in Mustadrak of Hakim al-Nishabouri. But I read that one narrator in his chain of the narration has been dismissed as a liar and fabricator by Imam Nasa'i and other Sunni scholars: Isma'il ibn Abi Owais (إِسْمَاعِيلُ بْنُ أَبِي أُوَيْسٍ). His father ibn Abi Owais ابْنُ أَبِي أُوَيْسٍ who is relied by Bukhari has also been weakened by an early Sunni scholar, Ibn Mu'in.
Interestingly Hakim himself feels the urge to corroborate the hadith by one from Abu Huraira who himself is a controversial source to begin with. But, anyway, this source has been given for Abu Huraira version. But I read there is one Salih ibn Musa ( صَالِحُ بْنُ مُوسَى) in the chain who has been weakened by a number of Sunni Imams including Ibn Muin, Nasai and Asqalani.
Another source for this hadith has been mentioned to come from a hadith book called At-Tamhid which is a commentary on Muwataa but this version too has been dismissed for including a fabricator named, Kathir ibn Abd Allah (کثیر بن عبدالله), according to my sources.
My question is what is the contemporary or final Sunni scholarly position on this hadith? Has the 'sunnah' version of the hadith been considered reliable by them or rejected in the light of the above objections, and why?
This would be apart from other troubling questions about this version including the suspicious similarity between its wording and that of the Ahl al-Bayt version.