The screen shoot below is from the suggested edit review queue. The name of the actual reviewers have been redacted to protect the guilty.
IMHO, one of the reviewers shows really bad judgement by approving this one. Not only is the proposed edit a vulgarism that never should be permitted on this site, but it is deliberaly inserted in a manner that vandalizes the original text.
As it turns there was one more vote for rejection than for approval, so the suggested edit ended up being rejected.
But I think this example shows that the community moderation system is vulnerable and depends on the assumption that community moderators is of high quality and able to show good judgement. If the majority of the community moderators is lacking in quality, serious breakage may occur.
The only "qualification" I know about for being a community moderator for suggested edits is to have earned 2000 experience points.
Are there other "checks and balances" in place to ensure high quality and good judgement being the norm for community moderators?