CVE-2026-26278
7.5 · HIGHOverview
CVE-2026-26278 is a high-severity vulnerability affecting naturalintelligence fast-xml-parser. It was published on February 19, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. In versions 4.1.3 through 5.3.5, the XML parser can be forced to do an unlimited amount of entity expansion. With a very small XML input, it’s possible to make the parser spend seconds or even minutes processing a single request, effectively freezing the application. Version 5.3.6 fixes the issue. As a workaround, avoid using DOCTYPE parsing by `processEntities: false` option.
Remediation
Check the references section for vendor advisories and patches from naturalintelligence. Update fast-xml-parser to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| naturalintelligence | fast-xml-parser | >= 4.1.3, < 5.3.6 | Affected |
References
Frequently Asked Questions
What is CVE-2026-26278?
CVE-2026-26278 is a high-severity vulnerability affecting naturalintelligence fast-xml-parser. It was published on February 19, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-26278?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-26278?
Check the references section for vendor advisories and patches from naturalintelligence. Update fast-xml-parser to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-26278?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-26278 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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