It's a security release:

Changes Since Opera 9.24 [opera.com]
Security

Fixed an issue where plug-ins could be used to allow cross domain scripting, as reported by David Bloom. Details will be disclosed at a later date.

Fixed an issue with TLS certificates that could be used to execute arbitrary code, as reported by Alexander Klink (Cynops GmbH). Details will be disclosed at a later date.

Rich text editing can no longer be used to allow cross domain scripting, as reported by David Bloom. See our advisory.

Prevented bitmaps from revealing random data from memory, as reported by Gynvael Coldwind. Details will be disclosed at a later date.
Miscellaneous

Fixed a problem where malformed BMP files could cause Opera to temporarily freeze.