Microsoft made a change to Outlook that has not allowed inline SVG images to be displayed. The reason they made the change was that hackers began using inline SVG images to perform attacks on people. You now will see a blank space instead of the image. Nice decision, right?
I suppose it will always appear that Microsoft made the decision to block inline SVG images in Outlook.
• We expect everyone will receive the update by mid-October 2025.
• Microsoft said that less than 0.1% of images viewed in Outlook are inline SVG images thus the overwhelming majority of users won’t even notice.
• If Microsoft blocks an inline SVG image, the user will simply see a blank space instead of an image.
• Normal images like PNG or JPG will appear just fine.
• Only inline SVGs (image files coded directly into the body of the email) are blocked.
This isn’t the first time Microsoft have initiated this type of blocking, Microsoft has blocked Macros, ActiveX, and more previously for the same reason which was a hacker abused them.
Here's the good news: very few people use inline SVG images in emails, so this news won't have a big impact on most people.
If your organization uses inline SVG images and email templates today, switch them to PNG or JPG. That's it.
And for the common person, if you see a blank space in an email, don't worry about it. It just means that Outlook is blocking something that could have been dangerous.
The next time you see a blank spot in an email, just smile, Outlook probably just saved you from being a victim of a cybercrime.
Why Did Microsoft Make This Change?
SVG means Scalable Vector Graphics usually because they are sharp at any size they are viewed. Hackers, however, started to embed malicious code into these bad images which could be processed through email to trick your users or steal data.I suppose it will always appear that Microsoft made the decision to block inline SVG images in Outlook.
How the Roll Out Will Work
• They began rolling this out in September 2025.• We expect everyone will receive the update by mid-October 2025.
• Microsoft said that less than 0.1% of images viewed in Outlook are inline SVG images thus the overwhelming majority of users won’t even notice.
• If Microsoft blocks an inline SVG image, the user will simply see a blank space instead of an image.
What Remains Functional
• When someone sends an SVG via attachment, you will still be able to open them.• Normal images like PNG or JPG will appear just fine.
• Only inline SVGs (image files coded directly into the body of the email) are blocked.
Considerations
Threat actors continue to find sneaky ways to attack, and inline SVGs were their latest version. By blocking inline SVGs, Microsoft is doing its part to protect Outlook users.This isn’t the first time Microsoft have initiated this type of blocking, Microsoft has blocked Macros, ActiveX, and more previously for the same reason which was a hacker abused them.
Here's the good news: very few people use inline SVG images in emails, so this news won't have a big impact on most people.
My Take
To be honest, I'm happy about this change. Would I rather see fancy icons in emails, or would I rather have a more secure inbox? Easy decisionIf your organization uses inline SVG images and email templates today, switch them to PNG or JPG. That's it.
And for the common person, if you see a blank space in an email, don't worry about it. It just means that Outlook is blocking something that could have been dangerous.
In Closing
Microsoft Outlook is now blocking inline SVG images to stop bad actors from exploiting them. It's a small change but a meaningful way to improve security.The next time you see a blank spot in an email, just smile, Outlook probably just saved you from being a victim of a cybercrime.