CVE-2025-45526 Denial of service in microlight
An attacker can cause browser crashes or unresponsiveness by tricking users into visiting a page with excessively large content in microlight elements.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-45526?
CVE-2025-45526 is a low-severity denial of service vulnerability in asvd microlight, published on 17 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A denial of service (DoS) vulnerability has been identified in the JavaScript library microlight version 0.0.7. This library, used for syntax highlighting, does not limit the size of textual content it processes in HTML elements with the microlight class. When excessively large content (e.g., 100 million characters) is processed, the reset function in microlight.js consumes excessive memory and CPU resources, causing browser crashes or unresponsiveness. An attacker can exploit this vulnerability by tricking a user into visiting a malicious web page containing a microlight element with large content, resulting in a denial of service. NOTE: this is disputed by multiple parties because a large amount of memory and CPU resources is expected to be needed for content of that size.
Weakness: CWE-770
Which versions are affected by CVE-2025-45526?
How do I fix CVE-2025-45526?
No fix has been published for CVE-2025-45526 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-45526 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-45526 exists.