Since Permalinks that contain Cyrillic may cause problems on some server setups, this plugin will work around this problem by updating the automatic Post Slug generation code. In this way, posts which have a title in Cyrillic will have permlinks transliterated in Latin characters.

Cyr2Lat Slugs

Converts Cyrillic letters in post slugs to human-readable Latin phonetic equivalent.

pbosakov

This plugin will automatically transliterate permalink URLs when you save a new page or post with a title in the Cyrillic script. 
Romanization presets are available for all the major languages using the Cyrillic script: Russian, Ukrainian, Kazakh, Belarussian, Serbian, Tajik, Bulgarian, Kyrgyz, Bosnian, Mongolian, and Macedonian. 
The plugin can also romanize permalinks for any pre-existing posts, categories, products or other items with a title written in Cyrillic. 
Only UTF-8 encoding is supported.

Cyrillic Permalinks

Automatically transliterates Cyrillic letters in permalinks to their Latin phonetic equivalent. Multi-language. Can convert pre-existing permalinks.

Cyr2Lat Slugs vs Cyrillic Permalinks