CVE-2025-45526: A denial of service (DoS) vulnerability has been identified in the JavaScript library microlight version 0.0.7. This library, used for syntax highligh...

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.

Metrics

CVSS 3.1

2.9/10

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

0.12%

2.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

References

Timeline

Published: Jun 17, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-45526?

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.

How severe is CVE-2025-45526?

CVE-2025-45526 has a CVSS score of 2.9/10 (LOW severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.

How do I fix CVE-2025-45526?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.