I think the "yellow" on top of the thorax is just reflected light. V. squamosa has a very unique abdominal pattern, and this specimen does not have that. I'd vote for either V. maculifrons or V. germanica off the top of my head. Those are certainly the most common species in the east.

It's quite true that it's VERY difficult to tell apart both species from this angle. Ironically, the antennae are hiding most of the space between clypeus and frontal yellow spot, which would have allowed an immediate identification.
But, I have a very long experience with V. germanica, dating back to the late seventies. I've caught hundreds, maybe thousands of workers of this species, reared colonies in semi-captivity for several years, and so on. Therefore, as soon as I saw this worker, I "felt" it was not a germanica.
Now I can explain why: look at the first abdominal tergite, just above the left folded wing. The left part of the central black spot is visible there. Very rarely, some smallish, especially melanic, germanica workers have a very similar one, i.e broadly anchor shaped. But then, the humeral yellow bands on the pronotum and the scrobal yellow spots on the mesopleura are much less developped than on this specimen, where they are almost confluent.
Therefore, this worker can be attibuted confidently to V. maculifrons.