To a limited extent, yes — that’s exactly what exposure adjustment tools are for. But it’s not the same as getting the exposure right in-camera.

If nothing important is clipped, small corrections are often fine. RAW files give you much more flexibility than JPEGs.

General rule:

• RAW: best for recovering small exposure errors
• JPEG: much less forgiving

Typical results:

• Underexposure: can usually be brightened, but noise increases; JPEG may also show banding/artifacts
• Overexposure: harder to fix, especially in JPEG; RAW may recover a little highlight detail, often less than about a stop

Even if the histogram doesn’t touch the edges, tiny blown highlights may not be obvious on the histogram, so some detail can still be lost.

Also, brightening an underexposed image in post usually gives more noise than using a higher ISO in-camera for the same shutter speed and aperture.

So: yes, minor exposure errors can often be corrected, especially with RAW, but incorrect exposure can still reduce quality. If you can re-shoot, do that. In difficult lighting, bracketing is a good idea.