CVE-2026-73569
CVE-2026-73569 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-776.
Key facts
- Severity: High (CVSS 4.0 base score 8.7)
- EPSS exploit prediction: 0% (31st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-776
- Published:
- Last modified:
Description
fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. From 5.9.3 until 5.10.1, src/xmlparser/OrderedObjParser.js processes multiple DOCTYPE declarations within a single XML document and passes each declaration's entities through addInputEntities(). addInputEntities() resets maxTotalExpansions and maxExpandedLength every time it is called, allowing additional DOCTYPE declarations to repeatedly reset the configured entity-expansion limits during one parse operation. A crafted XML document can then cause excessive CPU use, event-loop blocking, memory exhaustion, and process termination. This issue is fixed in version 5.10.1.
Frequently asked questions
- What is CVE-2026-73569?
- fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. From 5.9.3 until 5.10.1, src/xmlparser/OrderedObjParser.js processes multiple DOCTYPE declarations within a single XML document and passes each declaration's entities through addInputEntities(). addInputEntities() resets maxTotalExpansions and maxExpandedLength every time it is called, allowing additional DOCTYPE declarations to repeatedly reset the configured entity-expansion limits during one parse operation. A crafted XML document can then cause excessive CPU use, event-loop blocking, memory exhaustion, and process termination. This issue is fixed in version 5.10.1.
- How severe is CVE-2026-73569?
- CVE-2026-73569 has a CVSS 4.0 base score of 8.7, rated high severity.
- Is CVE-2026-73569 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-73569?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-73569 published?
- CVE-2026-73569 was published on 2026-08-13.
References
- https://github.com/NaturalIntelligence/fast-xml-parser/commit/4e546e03987662de5495d050b5fba26bea65383f
- https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.10.1
- https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-8r6m-32jq-jx6q
Other CWE-776 vulnerabilities
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- CVE-2022-23640 — Critical (CVSS 9.8): Excel-Streaming-Reader is an easy-to-use implementation of a streaming Excel reader using Apache POI. Prior to…
- CVE-2014-2228 — Critical (CVSS 9.8): The XStream extension in HP Fortify SCA before 2.2 RC3 allows remote attackers to execute arbitrary code via unsafe…
- CVE-2013-4335 — Critical (CVSS 9.8): opOpenSocialPlugin 0.8.2.1, > 0.9.9.2, 0.9.13, 1.2.6: Multiple XML External Entity Injection Vulnerabilities
- CVE-2021-23926 — Critical (CVSS 9.1): The XML parsers used by XMLBeans up to version 2.6.0 did not set the properties needed to protect the user from…
- CVE-2020-24590 — Critical (CVSS 9.1): The Management Console in WSO2 API Manager through 3.1.0 and API Microgateway 2.2.0 allows XML Entity Expansion attacks.