Process termination via reset entity expansion counters
Published Aug 13, 2026 · Updated Aug 13, 2026
XML entity expansion in Natural Intelligence fast-xml-parser 5.9.3 through 5.10.0 allows remote attackers to terminate its host process. OrderedObjParser.js sends each DOCTYPE's entities to addInputEntities(), which resets maxTotalExpansions and maxExpandedLength instead of preserving counters across the parse. The application must parse attacker-controlled XML with entity processing enabled; repeated declarations can exhaust CPU or memory, block the event loop, and terminate the process.
Summary
What happened
XML entity expansion in Natural Intelligence fast-xml-parser 5.9.3 through 5.10.0 allows remote attackers to terminate its host process. OrderedObjParser.js sends each DOCTYPE's entities to addInputEntities(), which resets maxTotalExpansions and maxExpandedLength instead of preserving counters across the parse. The application must parse attacker-controlled XML with entity processing enabled; repeated declarations can exhaust CPU or memory, block the event loop, and terminate the process.
The record
- CVE
- CVE-2026-73569
- Published
- Aug 13, 2026
- Updated
- Aug 13, 2026
- Vendor
- Natural Intelligence
- Product
- fast-xml-parser
- Classifications
- CWE-776, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 13, 2026CVE publishedPublication date reported by the CVE source.
- Aug 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 5.9.3, < 5.10.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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