XML Entity Expansion

Overview fast-xml-parser is a Validate XML, Parse XML, Build XML without C/C++ based libraries Affected versions of this package are vulnerable to XML Entity Expansion in the replaceEntitiesValue function, which doesn't protect unlimited expansion of numeric entities the way it does DOCTYPE data ...

GHSA-8GC5-J5RX-235R fast-xml-parser affected by numeric entity expansion bypassing all entity expansion limits (incomplete fix for CVE-2026-26278)

Summary The fix for CVE-2026-26278 added entity expansion limits maxTotalExpansions, maxExpandedLength, maxEntityCount, maxEntitySize to prevent XML entity expansion Denial of Service. However, these limits are only enforced for DOCTYPE-defined entities. Numeric character references &NNN; and &xH...

PT-2026-25995

Name of the Vulnerable Software and Affected Versions fast-xml-parser versions 4.0.0-beta.3 through 5.5.5 Description fast-xml-parser allows users to process XML from JavaScript objects without relying on C/C++ based libraries or callbacks. Versions 4.0.0-beta.3 through 5.5.5 contain a bypass tha...

CVE-2026-4224

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs...

CVE-2026-4224 Stack overflow parsing XML with deeply nested DTD content models

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs...

libexpat code issue vulnerabilities

libexpat is a streaming XML parser written in C language by the libexpat team. Versions of libexpat prior to 2.7.5 had code vulnerabilities; these vulnerabilities stemmed from allowing null pointer dereferencing when handling empty external parameter entity content...

Stack Overflow

fast-xml-parser is vulnerable to stack overflow vulnerability. The vulnerability is due to improper handling in the XML builder when preserveOrder:true is enabled, which allows an attacker to trigger a stack overflow and crash the application by providing crafted input data...

Linux Distros Unpatched Vulnerability : CVE-2026-27942

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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. Prior to versio...

📄 fast-xml-parser 5.3.5 Denial of Service

A denial of service vulnerability was identified in fast-xml-parser affecting versions 4.1.3 through 5.3.5. The issue arises from improper handling of XML Document Type Definitions DTD, specifically when processing internal entity expansion. An attacker can supply a crafted XML payload containing...

5-ifc-check-cli (1.0.0), 7ghost (>=4.11.2, <=4.11.46) +4210 more potentially affected by CVE-2026-27942 via fast-xml-parser (>=4.0.0-beta.2, <=4.5.3)

fast-xml-parser NPM version =4.0.0-beta.2, =4.11.2, =0.1.1, =0.0.2, =1.0.1, =1.0.0, =0.0.1, =1.0.0, =0.0.1, =0.0.1, =0.0.3 and more Source cves: CVE-2026-27942 Source advisory: OSV:GHSA-FJ3W-JWP8-X2G3...

GHSA-FJ3W-JWP8-X2G3 fast-xml-parser has stack overflow in XMLBuilder with preserveOrder

Impact Application crashes with stack overflow when user use XML builder with prserveOrder:true for following or similar input 'foo': 'bar': '@V': 'baz' Cause: arrToStr was not validating if the input is an array or a string and treating all non-array values as text content. What kind of...

@activepieces/piece-amazon-s3 (>=0.5.4, <=0.6.4), @activepieces/piece-amazon-ses (>=0.0.1, <=0.1.4) +1238 more potentially affected by CVE-2026-27942 via fast-xml-parser (>=5.0.1, <=5.3.7)

fast-xml-parser NPM version =5.0.1, =0.5.4, =0.0.1, =0.1.3, =0.5.3, =0.2.1, =13.1.4, =1.0.0, =1.9.12, =1.0.3, =1.1.31, =1.0.0, =1.0.0, =1.7.16, =1.10.0 and more Source cves: CVE-2026-27942 Source advisory: OSV:GHSA-FJ3W-JWP8-X2G3...

@activepieces/piece-amazon-s3 (>=0.5.4, <=0.6.4), @activepieces/piece-amazon-ses (>=0.0.1, <=0.1.4) +1238 more potentially affected by CVE-2026-27942 via fast-xml-parser (>=5.0.1, <=5.3.7)

fast-xml-parser NPM version =5.0.1, =0.5.4, =0.0.1, =0.1.3, =0.5.3, =0.2.1, =13.1.4, =1.0.0, =1.9.12, =1.0.3, =1.1.31, =1.0.0, =1.0.0, =1.7.16, =1.10.0 and more Source cves: CVE-2026-27942 Source advisory: GHSA-FJ3W-JWP8-X2G3...

5-ifc-check-cli (1.0.0), 7ghost (>=4.11.2, <=4.11.46) +4210 more potentially affected by CVE-2026-27942 via fast-xml-parser (>=4.0.0-beta.2, <=4.5.3)

fast-xml-parser NPM version =4.0.0-beta.2, =4.11.2, =0.1.1, =0.0.2, =1.0.1, =1.0.0, =0.0.1, =1.0.0, =0.0.1, =0.0.1, =0.0.3 and more Source cves: CVE-2026-27942 Source advisory: GHSA-FJ3W-JWP8-X2G3...

fast-xml-parser has stack overflow in XMLBuilder with preserveOrder

Impact Application crashes with stack overflow when user use XML builder with prserveOrder:true for following or similar input 'foo': 'bar': '@V': 'baz' Cause: arrToStr was not validating if the input is an array or a string and treating all non-array values as text content. What kind of...

CVE-2026-27942

A flaw was found in fast-xml-parser. A user can exploit this flaw by processing specially crafted XML data with the XML builder when the preserveOrder option is enabled. This can lead to a stack overflow, causing the application to crash and resulting in a Denial of Service DoS. Mitigation To...

bluez:fuzz_xml: Segv on unknown address in element_end

Project: https://github.com/bluez/bluez.git Detailed Report: https://oss-fuzz.com/testcase?key=4662824564752384 Project: bluez Fuzzing Engine: afl Fuzz Target: fuzzxml Job Type: aflasanbluez Platform Id: linux Crash Type: Segv on unknown address Crash Address: Crash State: elementend emitendeleme...

Buffer Overflow

Overview org.webjars.npm:fast-xml-parser is a Validate XML, Parse XML, Build XML without C/C++ based libraries Affected versions of this package are vulnerable to Buffer Overflow via the XMLBuilder when preserveOrder:true is set. An attacker can cause the application to crash by providing special...

Buffer Overflow

Overview fast-xml-parser is a Validate XML, Parse XML, Build XML without C/C++ based libraries Affected versions of this package are vulnerable to Buffer Overflow via the XMLBuilder when preserveOrder:true is set. An attacker can cause the application to crash by providing specially crafted input...

5-ifc-check-cli (1.0.0), 7ghost (>=4.11.2, <=4.11.46) +4210 more potentially affected by CVE-2026-27942 via fast-xml-parser (>=4.0.0-beta.2, <=4.5.3)

fast-xml-parser NPM version =4.0.0-beta.2, =4.11.2, =0.1.1, =0.0.2, =1.0.1, =1.0.0, =0.0.1, =1.0.0, =0.0.1, =0.0.1, =0.0.3 and more Source cves: CVE-2026-27942 Source advisory: SNYK:JS-FASTXMLPARSER-15353391...