Kourtney Kardashian is being indirectly blasted by the Mayor of Malibu -- who says folks working on behalf of her company appear to have gotten a rubber-stamped "A-OK" for a shindig in the 11th hour ... by none other than the City itself.

Mayor Bruce Silverstein laid it all out on Facebook Saturday -- detailing what he claims was a shady sign-off on a permit that allowed Kourtney's camp to host a private event at a home they rented in the Mayor's neighborhood ... which he later came to learn was tied to her Poosh brand.

It's worth reading his post to get the full context of what he's alleging here, but essentially -- it amounts to preferential treatment that he says is far too often granted to the rich and famous of Malibu. This time, he says it just so happened to work out for a Kardashian.

As for what he's specifically fuming over ... Silverstein says when he noticed the event getting set up at this empty house next door this week -- with truckloads of crap getting unloaded -- he asked what was going on ... and says he was told it was an influencer event. The Mayor says he informed the organizers that they needed a permit for that sort of thing -- and then proceeded to follow up with City staff to see if that was actually happening.

We'll spare you all the details, but basically ... the Mayor alleges that the City approved a Special Events Permit for the event planners working on behalf of Poosh -- and he goes on to claim that it seems to have been green-lit in record time, and under what he claims are possible false pretenses ... as it pertains to what the event was described as, how many people would be attending, the setup/breakdown procedure and resident notice required.

And yet, the Mayor claims everyone appears to have just looked the other way on all of it -- and he suspects all of this was done to appease a high-profile resident of the area.

The Mayor says he's disheartened by this -- as he goes on to explain that the regular citizens of Malibu hardly ever get the red carpet rolled out for them for things they wanna do -- having to wait weeks for a permit, as he notes -- but for a celeb ... immediate turnaround. He also says these type of events are a huge headache for the normies -- both in a safety capacity, but also as a general nuisance when it comes to noise, traffic, etc.

Silverstein says this is part of a much larger issue that he aims to address soon at the next City Council meeting ... and while he certainly seems upset with Kourtney and/or the people working with her on this particular get-together, he's much angrier at the powers that be that he suggests are willing to bend the knee at a moment's notice ... a culture he's tired of.

A couple points worth noting ... Poosh documented their Malibu bash on social media (it's all over their IG Story) but it's not clear if Kourtney herself attended it. Silverstein doesn't say she did or didn't ... but he does sound angry that her brand was given a clear path to seemingly do what it wanted at the drop of a dime -- at least according to him, anyway.

One last nugget that's worth mentioning ... we've learned that the Poosh party was actually put together via a major PR agency (Harper Sloane) -- so Kourtney's involvement in this is truly unknown at this point. Yes, she's the face of the company -- but we have no idea whether she herself knew about this event or what her participation in it was, if any.