If you own a Samsung Galaxy smartphone, there’s something you need to do—now. Samsung has issued an urgent security warning following the discovery of a serious vulnerability affecting almost every modern Galaxy device. The company has revised its September security update and will now roll out a fix for all eligible phones. So, what’s going on?
Table of Contents
Threat
The issue is tied to a critical vulnerability known as CVE-2025-21043. It was flagged by WhatsApp and is similar to CVE-2025-55177, the zero-day vulnerability that recently hit Apple’s iPhones. What makes this particular threat even more concerning is that Samsung confirmed the exploit has already been used in real-world attacks. In other words, it’s not theoretical—it’s actively being used to target Galaxy users.
The root of the problem lies in a third-party image-parsing library called libimagecodec.quram. This software has a flaw—specifically an out-of-bounds write vulnerability—that allows attackers to execute malicious code remotely on your phone. Once inside, they could potentially access your private data, messages, and stored files.
Scope
The vulnerability affects Galaxy phones running Android 13, 14, 15, and even the upcoming Android 16. That’s a huge swath of devices, especially when you consider that WhatsApp, which is used by more than 3 billion people worldwide, is installed on nearly every Galaxy phone by default.
Security researcher Brian Thornton from Zimperium pointed out that this zero-day highlights how attackers are now focusing on mobile platforms as an entry point. In his words, “a closed-source image library created a broad risk across Samsung devices and the apps that depend on it.” That’s a serious red flag for anyone with a Galaxy device.
Response
Both Samsung and WhatsApp have issued patches to address the problem. If you have automatic updates turned off, you should manually check for software updates through your phone’s settings and install the latest security patch immediately. Then, don’t forget to reboot your device.
Nivedita Murthy from Black Duck also confirmed that the flaw could be exploited to gain full access to your device, including stored data. This is not the kind of vulnerability you can afford to ignore.
Here’s a quick look at what you need to know:
| Detail | Description |
|---|---|
| Vulnerability Code | CVE-2025-21043 |
| Affected Devices | Galaxy phones with Android 13+ |
| Risk Level | Critical |
| Vulnerable Component | libimagecodec.quram (image library) |
| Patches Released By | Samsung and WhatsApp |
| Fix Availability | Rolling out by device, region, carrier |
Delay
Unlike Apple, which can deploy iOS updates to all iPhones globally at once, Samsung’s rollout is slower and more complex. The update process depends on your phone model, region, and carrier. That means some users may be protected right away, while others might have to wait days—or even weeks—for their turn.
This fragmented update model is one of the biggest security disadvantages of Android compared to iOS. As Apple prepares to launch iOS 26 across all devices next week, many Galaxy users are still stuck waiting for One UI 8.
If your phone is on Samsung’s monthly update schedule, you’re in line for the patch. Just make sure you install it as soon as it’s available and restart your phone to ensure it takes effect.
So while Samsung is taking action quickly, it’s ultimately up to you to stay on top of updates and take control of your device’s security. With mobile threats growing faster than ever, a simple update can mean the difference between a safe device and a compromised one.
FAQs
Which phones are affected by this flaw?
Galaxy phones running Android 13 or newer.
What is CVE-2025-21043?
A critical flaw in an image-processing library.
Is WhatsApp the only app affected?
Possibly, but other apps using the same library may be at risk.
Has the exploit been used already?
Yes, Samsung confirmed it’s active in the wild.
How can I stay protected?
Install the latest update and reboot your device.
