(The fix and CVE number for this issue are unknown)
A specially crafted web-page can trigger a use-after-free vulnerability in Opera. This vulnerability was found a very long time ago, back when I did not keep organized records of my analysis, so unfortunately, I cannot speculate on the potential impact or exploitability.
As I mentioned, I did not keep detailed records of my analysis, so there is not much I can say about this vulnerability, other than that I did attempt to write an exploit. However, I do not know how successful this exploit was. I did not include it in my report to iDefense, so I am assuming it was not very successful.Sploit.
(I asked ZDI and iDefense if they were interested in Opera vulnerabilities before submitting them. ZDI responded that they was not, but iDefense accidentally said they were. After submitting my first vulnerability, iDefense explained that there had been a mistake on their side and that they were not in fact interested. However, they kindly offered to buy this vulnerability for a token reward, which I accepted).