{"id":"CVE-2026-27942","aliases":["CLSA-2026-1776818199","CLSA-2026-1781744119","CLSA-2026-1781744139","CLSA-2026-1789289706","CLSA-2026-1792454133","CLSA-2026-1792488947","DEBIAN-CVE-2026-27942","EUVD-2026-8811","GHSA-fj3w-jwp8-x2g3","ROOT-APP-NPM-CVE-2026-27942","UBUNTU-CVE-2026-27942"],"status":"published","title":"fast-xml-parser has stack overflow in XMLBuilder with preserveOrder","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","severity":{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00543,"percentile":0.46119,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-120"],"published":"2026-02-26T01:22:11Z","modified":"2026-11-05T13:28:24Z","fixes":[{"ecosystem":"npm","package":"fast-xml-parser","fixed_in":["5.3.8","4.5.4"],"sources":["ghsa","osv"]},{"ecosystem":"TuxCare:npm","package":"fast-xml-parser","fixed_in":["4.5.1-tuxcare.1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"@rootio/fast-xml-parser","fixed_in":["5.3.4-root.io.3","4.4.1-root.io.4","5.3.4-root.io.4","5.3.6-root.io.2","4.4.1-root.io.5","4.4.1-root.io.6","4.4.1-root.io.7","5.3.4-root.io.5","5.3.6-root.io.3","5.2.5-root.io.2","4.4.1-root.io.8","5.2.5-root.io.3","5.3.4-root.io.6","5.3.6-root.io.4","4.4.1-root.io.9","5.2.5-root.io.4","5.3.4-root.io.7","5.3.6-root.io.5","5.3.4-root.io.8","5.3.6-root.io.6","4.5.4-root.io.1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"fast-xml-parser","fixed_in":["4.4.1-aikido.9","5.2.5-aikido.4","5.3.4-aikido.7","5.3.6-aikido.5","5.3.4-aikido.8","5.3.6-aikido.6","4.5.4-aikido.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0"},{"fixed":"5.3.8"}]}]},{"source":"ghsa","ecosystem":"npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0-beta.0"},{"fixed":"4.5.4"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.5.3-tuxcare.0"},{"fixed":"4.5.3-tuxcare.2"}]}],"versions":["4.5.3","4.5.3-tuxcare.1"],"bundled":2},{"source":"osv","ecosystem":"TuxCare:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.2.7-tuxcare.0"},{"fixed":"4.2.7-tuxcare.1"}]}],"versions":["4.2.7"],"bundled":6},{"source":"osv","ecosystem":"TuxCare:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.4.0-tuxcare.0"},{"fixed":"4.4.0-tuxcare.1"}]}],"versions":["4.4.0"],"bundled":6},{"source":"osv","ecosystem":"TuxCare:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.5.1-tuxcare.0"},{"fixed":"4.5.1-tuxcare.1"}]}],"versions":["4.5.1"]},{"source":"osv","ecosystem":"TuxCare:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.2.5-tuxcare.0"},{"fixed":"5.2.5-tuxcare.1"}]}],"versions":["5.2.5"],"bundled":7},{"source":"osv","ecosystem":"TuxCare:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.4.1-tuxcare.0"},{"fixed":"4.4.1-tuxcare.1"}]}],"versions":["4.4.1"],"bundled":3},{"source":"osv","ecosystem":"Debian:12","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-10","11.4.0+dfsg2+~cs35.7.26-11","11.4.0+dfsg2+~cs35.7.26-12","11.4.0+dfsg2+~cs35.7.26-13","11.4.0+dfsg2+~cs35.7.26-14","11.4.0+dfsg2+~cs35.7.26-15","11.4.0+dfsg2+~cs35.7.26-16","11.4.0+dfsg2+~cs35.7.26-18","11.4.0+dfsg2+~cs35.7.26-19","11.4.0+dfsg2+~cs35.7.26-20","11.4.0+dfsg2+~cs35.7.26-21","11.4.0+dfsg2+~cs35.7.26-7","11.4.0+dfsg2+~cs35.7.26-8","11.4.0+dfsg2+~cs35.7.26-9"]},{"source":"osv","ecosystem":"Debian:13","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-13","11.4.0+dfsg2+~cs35.7.26-14","11.4.0+dfsg2+~cs35.7.26-15","11.4.0+dfsg2+~cs35.7.26-16","11.4.0+dfsg2+~cs35.7.26-18","11.4.0+dfsg2+~cs35.7.26-19","11.4.0+dfsg2+~cs35.7.26-20","11.4.0+dfsg2+~cs35.7.26-21"]},{"source":"osv","ecosystem":"Debian:14","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-13","11.4.0+dfsg2+~cs35.7.26-14","11.4.0+dfsg2+~cs35.7.26-15","11.4.0+dfsg2+~cs35.7.26-16","11.4.0+dfsg2+~cs35.7.26-18","11.4.0+dfsg2+~cs35.7.26-19","11.4.0+dfsg2+~cs35.7.26-20","11.4.0+dfsg2+~cs35.7.26-21"]},{"source":"osv","ecosystem":"npm","package":"fast-xml-parser","ranges":[{"type":"SEMVER","events":[{"introduced":"5.0.0"},{"fixed":"5.3.8"}]}]},{"source":"osv","ecosystem":"npm","package":"fast-xml-parser","ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0-beta.0"},{"fixed":"4.5.4"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"@rootio/fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.3.4-root.io.3"},{"fixed":"4.4.1-root.io.4"},{"fixed":"5.3.4-root.io.4"},{"fixed":"5.3.6-root.io.2"},{"fixed":"4.4.1-root.io.5"},{"fixed":"4.4.1-root.io.6"},{"fixed":"4.4.1-root.io.7"},{"fixed":"5.3.4-root.io.5"},{"fixed":"5.3.6-root.io.3"},{"fixed":"5.2.5-root.io.2"},{"fixed":"4.4.1-root.io.8"},{"fixed":"5.2.5-root.io.3"},{"fixed":"5.3.4-root.io.6"},{"fixed":"5.3.6-root.io.4"},{"fixed":"4.4.1-root.io.9"},{"fixed":"5.2.5-root.io.4"},{"fixed":"5.3.4-root.io.7"},{"fixed":"5.3.6-root.io.5"},{"fixed":"5.3.4-root.io.8"},{"fixed":"5.3.6-root.io.6"},{"fixed":"4.5.4-root.io.1"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"fast-xml-parser","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.1-aikido.9"},{"fixed":"5.2.5-aikido.4"},{"fixed":"5.3.4-aikido.7"},{"fixed":"5.3.6-aikido.5"},{"fixed":"5.3.4-aikido.8"},{"fixed":"5.3.6-aikido.6"},{"fixed":"4.5.4-aikido.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-7ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-10","11.4.0+dfsg2+~cs35.7.26-13ubuntu2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-18","11.4.0+dfsg2+~cs35.7.26-19"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"node-webfont","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.4.0+dfsg2+~cs35.7.26-13ubuntu2","11.4.0+dfsg2+~cs35.7.26-14","11.4.0+dfsg2+~cs35.7.26-15","11.4.0+dfsg2+~cs35.7.26-16build1","11.4.0+dfsg2+~cs35.7.26-18"]}],"products":[{"vendor":"naturalintelligence","product":"fast-xml-parser"}],"references":[{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-fj3w-jwp8-x2g3","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web","report"]},{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/pull/791","tags":["x_refsource_MISC","Issue Tracking","Patch","fix","web","report"]},{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/c13a961910f14986295dd28484eee830fa1a0e8a","tags":["x_refsource_MISC","Patch","fix","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27942","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-fj3w-jwp8-x2g3"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27942.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-27942","tags":["advisory"]},{"url":"https://github.com/NaturalIntelligence/fast-xml-parser","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-27942","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-27942","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-27942","title":"fast-xml-parser has stack overflow in XMLBuilder with preserveOrder","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","status":"published","published":"2026-02-26T01:22:11.383Z","modified":"2026-06-23T15:50:01.617Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low","assessor":"cna"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T14:19:49.199185Z"}],"euvd":[{"id":"EUVD-2026-8811","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","status":"published","published":"2026-02-26T01:22:11Z","modified":"2026-06-23T15:50:01Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"updated_at":"2026-11-02T18:20:33.324654Z"}],"ghsa":[{"id":"GHSA-fj3w-jwp8-x2g3","title":"fast-xml-parser has stack overflow in XMLBuilder with preserveOrder","description":"### Impact\nApplication crashes with stack overflow when user use XML builder with `prserveOrder:true` for following or similar input \n\n```\n[{\n    'foo': [\n        { 'bar': [{ '@_V': 'baz' }] }\n    ]\n}]\n```\n\nCause: `arrToStr` was not validating if the input is an array or a string and treating all non-array values as text content.\n_What kind of vulnerability is it? Who is impacted?_\n\n### Patches\nYes in 5.3.8\n\n### Workarounds\nUse XML builder with `preserveOrder:false` or check the input data before passing to builder.\n\n### References\n[_Are there any links users can visit to find out more?_](https://github.com/NaturalIntelligence/fast-xml-parser/pull/791)","status":"published","published":"2026-02-26T22:33:10Z","modified":"2026-03-06T22:00:11Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T14:39:32.329372Z"}],"nvd":[{"id":"CVE-2026-27942","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","status":"published","published":"2026-02-26T02:16:22.357Z","modified":"2026-06-17T10:27:56.887Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T14:12:07.027269Z"}],"osv":[{"id":"CVE-2026-27942","title":"fast-xml-parser has stack overflow in XMLBuilder with preserveOrder","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","status":"published","published":"2026-02-26T01:22:11.383Z","modified":"2026-10-28T02:31:13.461604354Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T15:45:00.180685Z"},{"id":"DEBIAN-CVE-2026-27942","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","status":"published","published":"2026-02-26T02:16:22.357Z","modified":"2026-10-01T03:03:21.388073301Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:53.877573Z"},{"id":"GHSA-fj3w-jwp8-x2g3","title":"fast-xml-parser has stack overflow in XMLBuilder with preserveOrder","description":"### Impact\nApplication crashes with stack overflow when user use XML builder with `prserveOrder:true` for following or similar input \n\n```\n[{\n    'foo': [\n        { 'bar': [{ '@_V': 'baz' }] }\n    ]\n}]\n```\n\nCause: `arrToStr` was not validating if the input is an array or a string and treating all non-array values as text content.\n_What kind of vulnerability is it? Who is impacted?_\n\n### Patches\nYes in 5.3.8\n\n### Workarounds\nUse XML builder with `preserveOrder:false` or check the input data before passing to builder.\n\n### References\n[_Are there any links users can visit to find out more?_](https://github.com/NaturalIntelligence/fast-xml-parser/pull/791)","status":"published","published":"2026-02-26T22:33:10Z","modified":"2026-09-10T03:50:34.765253793Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T15:46:46.39441Z"},{"id":"ROOT-APP-NPM-CVE-2026-27942","title":"CVE-2026-27942 in @rootio/fast-xml-parser - Patched by Root","description":"Root has patched CVE-2026-27942 in the @rootio/fast-xml-parser package for Root:npm. Multiple fixed versions available.","status":"published","published":"2026-06-30T07:39:47Z","modified":"2026-06-30T13:15:08.979437816Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:27.649662Z"},{"id":"UBUNTU-CVE-2026-27942","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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.","status":"published","published":"2026-02-26T02:16:00Z","modified":"2026-10-17T12:58:08.012183318Z","cvss":[{"version":"4.0","score":2.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T16:56:08.726452Z"},{"id":"CLSA-2026-1776818199","title":"TuxCare security update for fast-xml-parser (2 CVEs)","description":"TuxCare rebuilt fast-xml-parser to address 2 CVEs. Fixed in 4.5.3-tuxcare.2.","status":"published","published":"2026-08-04T14:52:27Z","modified":"2026-10-23T13:58:15.220404137Z","updated_at":"2026-11-02T15:43:44.009773Z"},{"id":"CLSA-2026-1781744119","title":"TuxCare security update for fast-xml-parser (6 CVEs)","description":"TuxCare rebuilt fast-xml-parser to address 6 CVEs. Fixed in 4.2.7-tuxcare.1.","status":"published","published":"2026-08-04T14:52:37Z","modified":"2026-10-15T09:45:51.439601431Z","updated_at":"2026-11-02T15:43:45.794021Z"},{"id":"CLSA-2026-1781744139","title":"TuxCare security update for fast-xml-parser (6 CVEs)","description":"TuxCare rebuilt fast-xml-parser to address 6 CVEs. Fixed in 4.4.0-tuxcare.1.","status":"published","published":"2026-08-04T14:52:38Z","modified":"2026-11-05T13:28:24.682022025Z","updated_at":"2026-11-05T16:37:45.64821Z"},{"id":"CLSA-2026-1789289706","title":"TuxCare security update for fast-xml-parser (1 CVE)","description":"TuxCare rebuilt fast-xml-parser to address 1 CVE. Fixed in 4.5.1-tuxcare.1.","status":"published","published":"2026-09-13T08:55:06Z","modified":"2026-10-15T09:48:03.857399596Z","updated_at":"2026-11-02T15:43:47.938828Z"},{"id":"CLSA-2026-1792454133","title":"TuxCare security update for fast-xml-parser (7 CVEs)","description":"TuxCare rebuilt fast-xml-parser to address 7 CVEs. Fixed in 5.2.5-tuxcare.1.","status":"published","published":"2026-10-19T23:55:33Z","modified":"2026-10-20T01:45:13.504283365Z","updated_at":"2026-11-02T15:43:54.378946Z"},{"id":"CLSA-2026-1792488947","title":"TuxCare security update for fast-xml-parser (3 CVEs)","description":"TuxCare rebuilt fast-xml-parser to address 3 CVEs. Fixed in 4.4.1-tuxcare.1.","status":"published","published":"2026-10-20T09:35:47Z","modified":"2026-10-20T13:45:11.480018298Z","updated_at":"2026-11-02T15:43:54.378946Z"}]}}