CVE-2026-25128 | fast-xml-parser has RangeError DoS Numeric Entities Bug

Exp

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. In versions 5.0.9 through 5.3.3, a RangeError vulnerability exists in the numeric entity processing of fast-xml-parser when parsing XML with out-of-range entity code points (e.g., `�` or `�`). This causes the parser to throw an uncaught exception, crashing any application that processes untrusted XML input. Version 5.3.4 fixes the issue.

Published: 2026-01-30 Last update: 2026-02-27 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-25128 is rated Exploit Available (50.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-25128

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-25128

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-28 0.03% 0.05% +0.02%
2 2026-02-18 0.07% 0.03% -0.05%
3 2026-01-31 — 0.07% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-25128

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-25128

GitHub Security Advisory for CVE-2026-25128

GHSA-37qj-frw5-hhjh · Severity: high · Ecosystem: npm — fast-xml-parser has RangeError DoS Numeric Entities Bug

OS Trackers for CVE-2026-25128

vendor priority summary link
debian unimportant CVE-2026-25128 unimportant priority: Debian including 1 source packages (node-webfont), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2026-25128
redhat medium — https://access.redhat.com/security/cve/CVE-2026-25128
suse high — https://www.suse.com/security/cve/CVE-2026-25128/
ubuntu medium CVE-2026-25128 medium priority: Ubuntu including 1 source packages (node-webfont), 4 status rows across 4 suites (jammy, noble, questing, upstream): needs-triage 2, DNE 1, not-affected 1. https://ubuntu.com/security/CVE-2026-25128

Affected software / configurations for CVE-2026-25128

Vendor Product Version Raw CPE
naturalintelligence fast-xml-parser >= 5.0.9, < 5.3.4 cpe:2.3:a:naturalintelligence:fast-xml-parser:*:*:*:*:*:*:*:*

References for CVE-2026-25128

cvelogic Threat Intelligence