Mozilla has stepped up its efforts to fix Firefox bugs before next week’s Pwn2Own hacking competition. Among the 10 bugs, eight were said to be critical.

Google has taken steps to fix bugs in its Web browser Chrome. It patched a total of 19 bugs in Chrome, of which three were deemed as medium and the other as high.

The fixes have been incorporated in the delayed releases of Firefox 3.6.14 and 3.5.17, and Thunderbird 3.1.8.

Mozilla issued fixes for 10 bugs in total, which ranged from JPEG decoding to JAVA script issues to memory corruption.

The measures by the Web browser providers come days before the fifth annual Pwn2Own competition, a hacking contest targeting Web browsers and mobile phones.

The contest has cash prizes for successful hacks.