Vulnerability-Lookup

UBUNTU-CVE-2026-27942 (CVE-2026-27942)

Vulnerability from osv_ubuntu – Published: 2026-02-26 02:16 – Updated: 2026-10-17 09:39 – Source website

Details

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

2.7 (Low)


                    
                      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

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-27942	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-27942	REPORT
	https://github.com/NaturalIntelligence/fast-xml-p…	REPORT
	https://github.com/NaturalIntelligence/fast-xml-p…	REPORT
	https://github.com/NaturalIntelligence/fast-xml-p…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "node-webfont",
            "binary_version": "11.4.0+dfsg2+~cs35.7.26-7ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "node-webfont",
        "purl": "pkg:deb/ubuntu/node-webfont@11.4.0+dfsg2+~cs35.7.26-7ubuntu1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "11.4.0+dfsg2+~cs35.7.26-7ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "node-webfont",
            "binary_version": "11.4.0+dfsg2+~cs35.7.26-13ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "node-webfont",
        "purl": "pkg:deb/ubuntu/node-webfont@11.4.0+dfsg2+~cs35.7.26-13ubuntu2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "11.4.0+dfsg2+~cs35.7.26-10",
        "11.4.0+dfsg2+~cs35.7.26-13ubuntu2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "node-webfont",
            "binary_version": "11.4.0+dfsg2+~cs35.7.26-19"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
        "name": "node-webfont",
        "purl": "pkg:deb/ubuntu/node-webfont@11.4.0+dfsg2+~cs35.7.26-19?arch=source\u0026distro=stonking"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "11.4.0+dfsg2+~cs35.7.26-18",
        "11.4.0+dfsg2+~cs35.7.26-19"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "node-webfont",
            "binary_version": "11.4.0+dfsg2+~cs35.7.26-18"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "node-webfont",
        "purl": "pkg:deb/ubuntu/node-webfont@11.4.0+dfsg2+~cs35.7.26-18?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "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"
      ]
    }
  ],
  "aliases": [],
  "details": "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.",
  "id": "UBUNTU-CVE-2026-27942",
  "modified": "2026-10-17T09:39:34Z",
  "published": "2026-02-26T02:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-27942"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-27942"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-fj3w-jwp8-x2g3"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser/pull/791"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser/commit/c13a961910f14986295dd28484eee830fa1a0e8a"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-27942"
  ]
}

CVE-2026-27942 (GCVE-0-2026-27942)

Vulnerability from cvelistv5 – Published: 2026-02-26 01:22 – Updated: 2026-06-23 15:50

Title

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

Summary

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

2.7 (Low)


                        
                          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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-02-26 15:48 UTC

CWE

CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7627 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/NaturalIntelligence/fast-xml-p…	x_refsource_CONFIRM
https://github.com/NaturalIntelligence/fast-xml-p…	x_refsource_MISC
https://github.com/NaturalIntelligence/fast-xml-p…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
NaturalIntelligence	fast-xml-parser	Affected: < 5.3.8

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-27942",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-26T15:48:57.198872Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-23T15:50:01.617Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "fast-xml-parser",
          "vendor": "NaturalIntelligence",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.3.8"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 2.7,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-120",
              "description": "CWE-120: Buffer Copy without Checking Size of Input (\u0027Classic Buffer Overflow\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-26T01:22:11.383Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-fj3w-jwp8-x2g3",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-fj3w-jwp8-x2g3"
        },
        {
          "name": "https://github.com/NaturalIntelligence/fast-xml-parser/pull/791",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/NaturalIntelligence/fast-xml-parser/pull/791"
        },
        {
          "name": "https://github.com/NaturalIntelligence/fast-xml-parser/commit/c13a961910f14986295dd28484eee830fa1a0e8a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/NaturalIntelligence/fast-xml-parser/commit/c13a961910f14986295dd28484eee830fa1a0e8a"
        }
      ],
      "source": {
        "advisory": "GHSA-fj3w-jwp8-x2g3",
        "discovery": "UNKNOWN"
      },
      "title": "fast-xml-parser has stack overflow in XMLBuilder with preserveOrder"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-27942",
    "datePublished": "2026-02-26T01:22:11.383Z",
    "dateReserved": "2026-02-25T03:11:36.689Z",
    "dateUpdated": "2026-06-23T15:50:01.617Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted