Galaxy S24 owners in the United States and Europe are getting an important new security update that quietly does a lot of heavy lifting in the background. Two months after the big Android 16-based One UI 8.0 rollout, Samsung is pushing out a fresh November 2025 security patch that focuses entirely on locking down your phone rather than adding flashy new features. 
If you own a Galaxy S24, Galaxy S24+, or Galaxy S24 Ultra, this is the next update you should be looking for.
The rollout began in Samsung’s home market of Korea and is now expanding to the US and European markets, with more regions expected to follow. This is typically how Samsung handles its updates: first test the firmware in a limited region, then expand once everything looks stable. That means if you have not yet seen the notification on your Galaxy S24 series device, it is likely just a matter of time before the patch hits your region as well.
You can recognize the update by looking for firmware that ends in CYK2. In the US and Europe, the download weighs a bit over 450 MB, which is relatively modest for a post-OS-release patch but still large enough to signal that serious under-the-hood work has been done. Because this is entirely a security-focused release and not a feature drop, you should not expect new interface tricks or visible tools, but you will be getting a safer phone.
How to install the November 2025 Galaxy S24 update
The update process is simple and takes just a couple of taps. On your Galaxy S24, S24+, or S24 Ultra, follow these steps:
- Open the Settings app.
- Scroll down and tap Software update.
- Select Download and install.
If the firmware ending in CYK2 is already available for your device and region, your phone will start downloading it. As always, it is smart to install updates while your battery is reasonably charged and, ideally, while you are connected to Wi-Fi so you do not burn through your mobile data allowance.
What the November 2025 security patch actually fixes
This release is the first patch for the Galaxy S24 series since Samsung shipped One UI 8.0 on top of Android 16. Instead of mixing in visual tweaks or new features, Samsung has dedicated this update entirely to security. Under the hood, it addresses a large batch of vulnerabilities affecting both Android itself and Samsung’s own One UI customizations.
On the Android side, the November 2025 security update fixes 25 distinct vulnerabilities. Two of these are classified as critical, which is the highest severity rating Google gives. One critical flaw affects devices running Android 13 and newer, while the other is specific to Android 16. The rest of the vulnerabilities patched in this round are all rated high risk, which means they could potentially be exploited to gain elevated privileges, access data, or destabilize the system. Notably, there are no medium- or low-severity issues included in this month’s package, underscoring how focused it is on the more serious threats.
Beyond Google’s Android framework, Samsung has patched nine security issues that are unique to Galaxy devices. These are problems that arise from Samsung’s own software layer and custom features – the parts of the system that differentiate Galaxy phones from other Android brands. Fixing these helps protect features like Samsung-specific system apps, custom services, and the deeper integration that One UI adds on top of stock Android.
Exynos devices also get important fixes
The update does not stop at phones, either. Samsung states that the November 2025 patch also addresses 11 vulnerabilities related to its Exynos chipsets. These chips power many Galaxy smartphones and wearable devices, and the issues in question appear to affect a wide range of Exynos hardware manufactured between 2019 and 2024. Even if you are using a model that does not run on Exynos in your region, these fixes still matter to the broader Galaxy ecosystem, especially if you also own a Samsung wearable or live in a market where Exynos variants are common.
Chip-level security flaws are particularly sensitive because they can sometimes be abused at a lower level than normal apps, potentially bypassing parts of the operating system’s protections. By shipping these Exynos-related fixes together with the Galaxy S24 series update, Samsung is closing off more avenues that attackers could theoretically use to compromise devices.
No new features, but big gains for safety
Some users may feel a bit underwhelmed when an update does not bring fresh animations, camera tricks, or customization options. However, security patches like this one are among the most important updates your phone ever receives. Every critical and high-risk vulnerability that gets fixed is one less potential loophole that malware, malicious websites, or targeted attackers can take advantage of.
In practical terms, installing the November 2025 Galaxy S24 update helps protect your sensitive data, from personal photos and chat logs to banking apps and work emails. It also reduces the risk of remote code execution exploits, privilege escalation bugs, and other vulnerabilities that can lead to data theft or unauthorized access. These are not the kinds of changes you can see, but they do make a real difference over time – especially as Android and Samsung’s services remain constantly connected to the internet.
Should Galaxy S24 owners update now?
Yes. Even though the November 2025 patch does not introduce visible new features, it is highly recommended that Galaxy S24, S24+, and S24 Ultra users install it as soon as it becomes available on their devices. This is especially true because the patch hits a concentration of critical and high-risk security flaws across Android, One UI, and Exynos chipsets.
If you have recently upgraded to Android 16 with One UI 8.0, this update can be seen as the first big security sweep that tightens everything up after the major platform transition. Installing it is a quick, low-effort step that pays off in long-term peace of mind. Once your phone reboots, you might not notice anything new – but your device will be better defended against modern threats, and that is exactly what you want from a good security update.
In short, when you see the CYK2 firmware waiting for your Galaxy S24 series phone, do not ignore it. Take a couple of minutes to download and install the November 2025 security patch and let it quietly do its job in the background: keeping your Galaxy safer, more stable, and ready for whatever comes next.