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.
CVE-2026-25896
CRITICALPre-NVD 9.39.3Elevated
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
9.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.3Exploit: NoneExposed: 0
A fix is available — apply it.
- CVSS v3
- 9.3
- EG Score
- 9.3(low)
- EPSS
- 35.7%
- KEV
- Not listed
Published
February 20, 2026
Last Modified
July 2, 2026
Advisory Details (10)
Auto-updated Jun 30, 2026🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github, redhat.
redhat
2441501 – (CVE-2026-25896) CVE-2026-25896 fast-xml-parser: fast-xml-parser: Cross-Site Scripting (XSS) due to improper DOCTYPE entity handling
https://bugzilla.redhat.com/show_bug.cgi?id=2441501redhat Patch Available
redhat Patch Available
redhat Patch Available
redhat Patch Available
github Patch Available🟡 PoC Available
Entity encoding bypass via regex injection in DOCTYPE entity names · Advisory · NaturalIntelligence/fast-xml-parser · GitHub
https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-m7jm-9gc2-mpf2github_release Patch Available
v5.3.5
Patch available: NaturalIntelligence/fast-xml-parser v5.3.5
https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.3.5github_commit Patch Available
commit ddcd0acf26dd (NaturalIntelligence/fast-xml-parser)
Patch available: NaturalIntelligence/fast-xml-parser v5.3.5 (contains commit ddcd0acf26dd)
https://github.com/NaturalIntelligence/fast-xml-parser/commit/ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69github_commit Patch Available
commit 943ef0eb1b2d (NaturalIntelligence/fast-xml-parser)
Patch available: NaturalIntelligence/fast-xml-parser v5.3.5 (contains commit 943ef0eb1b2d)
https://github.com/NaturalIntelligence/fast-xml-parser/commit/943ef0eb1b2d3284e72dd74f44a042ee9f07026eVendor Advisories for CVE-2026-25896(4)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:7128Red Hat Product SecurityHigh
Red Hat Security Advisory: RHACS 4.9.5 security and bug fix update
- RHSA-2026:7110Red Hat Product SecurityHigh
Red Hat Security Advisory: RHACS 4.8.10 security and bug fix update
- RHSA-2026:6802Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Developer Hub 1.9.3 release.
- RHSA-2026:6174Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Developer Hub 1.8.5 release.
Patch Availability(4)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | advanced-cluster-security/rhacs-main-rhel8:1775594119 | 2026-04-08 | redhat |
| redhat | advanced-cluster-security/rhacs-main-rhel8:1775594284 | 2026-04-08 | redhat |
| redhat | rhdh/rhdh-hub-rhel9:1775140647 | 2026-04-07 | redhat |
| redhat | rhdh/rhdh-hub-rhel9:1774545605 | 2026-03-30 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| fast-xml-parser | — | 5.3.5 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 14× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 04:42 UTCEG score recompute
- 2026-06-30 04:42 UTCVendor advisory
- 2026-06-30 04:31 UTCNVD updatefirst tracked
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat
Frequently asked(5)
What is CVE-2026-25896?
CVE-2026-25896 is a critical vulnerability published on February 20, 2026. 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…
When was CVE-2026-25896 disclosed?
CVE-2026-25896 was first published in the National Vulnerability Database on February 20, 2026, with the most recent update on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-25896 actively exploited?
CVE-2026-25896 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 35.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-25896?
CVE-2026-25896 has a CVSS v4.0 base score of 9.3 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-25896?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-25896, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-25896
Is Your Infrastructure Affected by CVE-2026-25896?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.