If a Flash 9 SWF loads two SWF files with different SWF version numbers from two distinct HTTP requests to the exact same URL (including query string arguments), then Adobe's Flash Player plug-in will try to dereference a null pointer. This issue affects at least versions 9.0.45.0, 9.0.112.0, 9.0.124.0, and 10.0.12.10 on Windows, OS X, and Linux. For browsers where plug-ins run in the same process (e.g., Internet Explorer 6 and 7, Firefox 3, and Safari 3 on Windows and OS X), this causes the entire browser process to crash. Sample code demonstrating this issue is available at http://www.mochimedia.com/~matthew/flashcrash/. On 2008.09.22, I submitted this issue to Adobe's JIRA bug tracking system, which recorded it as issue #FP-677. On 2008.09.23, the ticket was changed to private for security reasons, and Adobe told me they were able to reproduce the issue and were investigating it. On 2008.09.26, I told Adobe I planned on submitting this issue to BugTraq and asked if they had found any workarounds for users that I could include. On 2008.10.01, they told me they had resolved the problem and that a fix will be included in the next public update, but they did not provide any workarounds. Matthew Dempskyhttp://www.mochimedia.com