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Vulnerabilities

Vulnerability · CVE-2026-25896

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.

Published Feb 20, 2026 · catalog updated Sep 10, 2026 · fast-xml-parser allows users to

Check if you run it

No confirmed exploitation is on record for CVE-2026-25896. EPSS is 0.51%. Act only if a listed version of fast-xml-parser allows users to is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (fast-xml-parser allows users to).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.51%
Remediation
Advisory link
Affected products
cpe naturalintelligence/fast-xml-parser

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. From 4.1.3to before 5.3.5, a dot (.) in a DOCTYPE entity name is treated as a regex wildcard during entity replacement, allowing an attacker to shadow built-in XML entities (<, >, &, ", ') with arbitrary values. This bypasses entity encoding and leads to XSS when parsed output is rendered. This vulnerability is fixed in 5.3.5.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe naturalintelligence/fast-xml-parserversion unspecified

How to fix CVE-2026-25896

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-25896. EPSS is 0.51%. Act only if a listed version of fast-xml-parser allows users to is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-185; CWE-79: Cross-site Scripting (XSS). EPSS 0.51%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 20, 2026 · NIST NVD

    Detected

    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. From 4.1.3to before 5.3.5, a dot (.) in a DOCTYPE entity name is treated as a regex wildcard during entity replacement, allowing an attacker to shadow built-in XML entities ( , &, ", ') with arbitrary values. This bypasses entity encoding and leads to

  2. Sep 10, 2026 · NIST NVD

    Updated

    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. From 4.1.3to before 5.3.5, a dot (.) in a DOCTYPE entity name is treated as a regex wildcard during entity replacement, allowing an attacker to shadow built-in XML entities ( , &, ", ') with arbitrary values. This bypasses entity encoding and leads to

Sources

  • CVE.orgVulnerability recordCVE-2026-25896

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-25896

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDVulnerability recordCVE-2026-25896

    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. From 4.1.3to before 5.3.5, a dot (.) in a DOCTYPE entity name is treated as a regex wildcard during entity replacement, allowing an att

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.