CVE-2021-1826 Cross-site scripting in iOS and iPadOS
Attackers can execute arbitrary scripts in the victim's browser context via malicious web content, affecting Apple operating systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-1826?
CVE-2021-1826 is a medium-severity cross-site scripting vulnerability in Apple Ipados, published on 8 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. Processing maliciously crafted web content may lead to universal cross site scripting.
Weakness: CWE-79
Which versions are affected by CVE-2021-1826?
It affects 5 products.
Products include Apple Ipados, Apple Iphone Os, Apple Macos, Apple Tvos, Apple Watchos.
How do I fix CVE-2021-1826?
Apply the vendor's patch.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-1826 being exploited?
There is no known exploitation of CVE-2021-1826 in the wild and no public exploit code.
Other vulnerabilities in Apple Ipados
- CVE-2025-43300 Apple iOS, iPadOS, and macOS Out-of-Bounds Write
- CVE-2025-24201 Apple Multiple Products WebKit Out-of-Bounds Write
- CVE-2025-24085 Apple Multiple Products Use-After-Free
- CVE-2025-31200 Apple Multiple Products Memory Corruption
- CVE-2025-31201 Apple Multiple Products Arbitrary Read and Write
Sources
Also known as DEBIAN-CVE-2021-1826, GHSA-868x-c2ph-qm3r, UBUNTU-CVE-2021-1826.