CVE-2026-25896

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Source
https://cve.org/CVERecord?id=CVE-2026-25896
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-25896.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-25896
Aliases
Downstream
CGA (34)
CLEANSTART (8)
CLSA (4)
DEBIAN (1)
MINI (14)
ROOT (1)
UBUNTU (1)
Published
2026-02-20T20:57:48Z
Modified
2026-10-15T02:51:00Z
Severity
  • 9.3 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N CVSS Calculator
Summary
fast-xml-parser has an entity encoding bypass via regex injection in DOCTYPE entity names
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. 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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-185"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25896.json"
}
References

Affected packages

Git / github.com/naturalintelligence/fast-xml-parser

Affected ranges

Type
GIT
Repo
https://github.com/naturalintelligence/fast-xml-parser
Events
Introduced
292fb784334043214e29fa60adbb5630a36f5768
Fixed
fe9a85270122036ae22637167ce38a5f71b73a5f
Fixed
943ef0eb1b2d3284e72dd74f44a042ee9f07026e
Fixed
ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69
Database specific
Show details 
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:naturalintelligence:fast-xml-parser:*:*:*:*:*:*:*:*",
            "range":  [
                {
                    "introduced":  "4.1.3"
                },
                {
                    "fixed":  "5.3.5"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "range":  [
                {
                    "fixed":  "943ef0eb1b2d3284e72dd74f44a042ee9f07026e"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "range":  [
                {
                    "fixed":  "ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v5.3.5",
            "range":  [
                {
                    "fixed":  "fe9a85270122036ae22637167ce38a5f71b73a5f"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

v4.*
v4.1.3
v4.1.4
v4.2.0
v4.2.3
v4.2.4
v4.2.5
v4.2.6
v4.2.7
v4.3.0
v4.3.1
v4.3.2
v4.3.3
v4.3.4
v4.3.5
v4.3.6
v4.4.0
v4.4.1
v4.5.0
v4.5.1
v4.5.2
v5.*
v5.0.0
v5.0.2
v5.0.4
v5.0.6
v5.0.7
v5.0.9
v5.1.0
v5.2.0
v5.2.1
v5.2.2
v5.2.3
v5.2.5
v5.3.0
v5.3.1
v5.3.2
v5.3.3
v5.3.4

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-25896.json"