Announcing updates of Apr 21, 2026 for Java 26, 25, 21, 17, 11, and 8 - thoughts and resources

Himanshu, I will say first that no, this doesn't seem the right place--since you say that the issue started with your last update of CF. Maybe you thought it could be since you're asking about "jvm arguments", but what you refer to are not new args with THIS recent JVM update.

Still, you've written here already, so let's plow on. First, a few questions (you can use the numbers to offer your answers):

1) You don't clarify WHAT update was "the last update" you applied. Was it the one that came out last week, CF2023's update 19? If you don't have access to the CF admin, you can see the current CF update version by dumping CF's server.coldfusion.productversion variable. And do you know what update were you on BEFORE that? That could be significant to understanding your problem.

2) And as for what else may have changed, when you (or a colleague) updated your CF, did you ALSO happen to update your JVM that CF uses, as discussed in this post? If so, what JVM version does the CF admin show you now using (use the "settings summary" page on the first Admin "settings" button). If you don't have access to the admin, dump cf's server.system.properties["java.version"] variable.

And do you know what JVM version it was using before?

3) And what OS is CF running on? Windows? Linux? Mac? And what locale/language is your CF server set for?

Whenever trying to understand "why did things break", it's CRUCIAL to understand whatever was changed. Often people think it was one thing (like in your case, "the last cf update"), when it may well be that or something else, or a combination of things. Or people may pose "answers", but they may not suit YOUR setup.

Indeed, to your asking about adding the jvm arg "-Dfile.encoding=UTF-8", I'll assume you mean you find that none is set currently, right? I'll clarify for readers that that there is NO arg of that name set for CF (2023 or 2025) by default.

And therefore its value is decided upon by Java (not CF)--and Java decides based on not only your Java version but also your OS (thus my questions above). More specifically, note that for Java 18 and above, it now DEFAULTS to utf-8 for ALL OS's. But since C2023 runs (and is supported only to run) on Java 17 (while CF2025 is supported only to run on Java 21, so this arg/value you propose should NOT be needed for CF2025.)

4) So are you aware of what your CURRENT jvm file.encoding value is? I would propose it's always wise to know what value you are changing FROM when making such jvm changes. Also, it may prove helpful for you (or us) to know.

If you have access to the CF admin, it's shown there on that same "settings summary" page as "Java File Encoding". If you don't have access to the admin, dump out the value of CF's server.system.properties["file.encoding"] variable. For my CF2023 on Windows it reports being Cp1252. If yours is something else, perhaps that's worth digging into.

5) Finally, you didn't say what your errors were beyond "rendering utf-8 chars". Is that in outputting html, from CF pages? Or was it maybe about CF accessing files? Or accessing data returned from external applications/api's?

FWIW, many such operations have their own way to set the encoding for that specific operation, which might be another solution (or even perhaps another explanation for problems). And beyond looking at the CFML reference docs, see also the discussion in the CF Developer's Guide about such character encoding, at https://tinyurl.com/ye25mj2p

I realize you probably didn't want to be asked a lot of questions. You just want to know if your sites will break if you make this change. I'm afraid I simply can't tell you that. I'm not sure if anyone else can (but perhaps they may).

Indeed, finally, I can't help but offer also that if you're asking this because you only have a prod environment and so fear making the change, I would push back STRONGLY that this is the EXACT reason one should have a dev or test environment, so as to mimic prod (as well as possible), such that you could make the change there and find your answer without such grave risk.

Let's see if any of the above may have helped you, or if your answers to the questions may help me or others to help you further.

Thanks for the kind regards. As for your issue, it's helpful that you've confirmed the problem is not new since any particular cf or Java update.

That said, it's really hard to know then what has led to the change in behavior.

Believe it or not, since you've started editing old code (if seems), note that these character encoding problems can happen BECAUSE OF YOUR EDITOR. And of course, you may have different devs using different editors. One may be stubbornly sticking to a very old one which may be introducing these problems, when they edit code.

Or the problem could be in your database. There are char encoding features in most DBs, settable at the db server, db, table, or column level. Similarly, the change could be about data being sent to the database across the cf jdbc connection, and that has configurability regarding character encoding.

I don't think there's going to be one magic change in cf or its jvm args that will fix this, but again perhaps someone with more familiarity with the problem may say otherwise.

You may want to ask across a far broader set of eyes--even just within the cf community. I list several places where you can ask such questions at cf411.com/cfsocialhelp. Let us know here if you end up with a simple explanation and solution.