VulnerabilityPublished 5 Apr 2023Updated 3 Dec 2025

CVE-2023-0842: xml2js · Prototype Pollution

Affects xml2jsSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.4% chance of exploitation in 30 days – higher than 72% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Apr 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
npmxml2js`pkg:npm/xml2js`Other threats	Affected =0.4.23	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. 2. Implement strict input validation and sanitization to reject or neutralize __proto__ keys or other prototype pollution vectors in incoming XML or JSON data before parsing. 3. Employ runtime security controls such as object freezing or using libraries that prevent prototype pollution. 4. Conduct code audits and dependency scans to identify usage of vulnerable xml2js versions across all projects. 5. Use application-level monitoring to detect anomalous behavior that could indicate exploitation attempts. 6. Educate development teams about prototype pollution risks and secure coding practices related to object property handling in JavaScript. 7. Consider isolating or sandboxing components that parse untrusted XML to limit potential damage.

Description

CVE-2023-0842 is a medium severity prototype pollution vulnerability in xml2js version 0.4.23. It allows an unauthenticated remote attacker to modify or add properties to JavaScript objects by exploiting improper validation of JSON keys, specifically the __proto__ property. This can lead to integrity issues in applications using the vulnerable xml2js version, potentially causing unexpected behavior or security bypasses. The vulnerability does not impact confidentiality or availability directly and requires no user interaction. No known exploits are currently reported in the wild. European organizations using xml2js 0.4.23 in their Node.

Impact

For European organizations, the primary impact is on the integrity of applications that use xml2js version 0.4.23 to parse XML data, especially when processing untrusted or user-supplied input. Prototype pollution can lead to unexpected application behavior, potential privilege escalation within the application context, or bypass of security controls relying on object properties. While confidentiality and availability are not directly affected, the integrity compromise can facilitate further attacks or data manipulation. Organizations in sectors such as finance, healthcare, and critical infrastructure that rely on Node.js applications for data processing could face operational risks and compliance issues if this vulnerability is exploited. Additionally, supply chain risks exist if vulnerable xml2js versions are embedded in third-party software components. The absence of known exploits reduces immediate risk but does not eliminate the need for prompt remediation.

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (opens in a new tab)
Variant weakness
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
Implementation
By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
Architecture and Design
By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
Implementation · Input Validation
When handling untrusted objects, validating using a schema can be used.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
Manipulating User-Controlled Variables (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Dec 2025, 20:52 UTC

WeaknessesCWE-1321

Technical details

References

Community reviews

Related threats