CVE-2025-64718VulnerabilityPublished 13 Nov 2025Updated 29 Jan 2026

CVE-2025-64718: nodeca js-yaml · Prototype Pollution

Affects nodeca js-yamlSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.14.2 when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.14.2

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 13 Nov 2025
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 2026-10-25.

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

Upgrade nodeca js-yaml to 3.14.2.

Affected software

Product	Affected	Fixed in
npmjs-yaml`pkg:npm/js-yaml`Other threats	Affected <3.14.2	Fixed in 3.14.2

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

AI-suggested

European organizations should immediately identify all instances of js-yaml usage in their software stacks, including direct dependencies and transitive dependencies in Node.js projects. Upgrading to js-yaml versions 4.1.1 or 3.14.2 is the most effective mitigation. For environments where immediate upgrade is not feasible, running Node.js with the --disable-proto=delete flag can help prevent prototype pollution attacks by disabling prototype deletion operations. Additionally, migrating to the Deno runtime environment can provide built-in protection against such pollution. Organizations should also implement strict input validation and sanitization for YAML inputs, especially if sourced from untrusted or external origins. Employing runtime application self-protection (RASP) or behavior monitoring to detect anomalous prototype modifications can provide additional defense layers. Regular dependency audits and integrating software composition analysis (SCA) tools into CI/CD pipelines will help detect vulnerable versions early. Finally, educating developers about the risks of prototype pollution and secure YAML parsing practices is crucial to prevent future vulnerabilities.

Description

js-yaml is a JavaScript YAML parser and dumper. In js-yaml before 4.1.1 and 3.14.2, it's possible for an attacker to modify the prototype of the result of a parsed yaml document via prototype pollution (`__proto__`). All users who parse untrusted yaml documents may be impacted. The problem is patched in js-yaml 4.1.1 and 3.14.2. Users can protect against this kind of attack on the server by using `node --disable-proto=delete` or `deno` (in Deno, pollution protection is on by default).

Impact

For European organizations, this vulnerability poses a risk primarily to the integrity of applications that parse YAML input using vulnerable js-yaml versions. Attackers could manipulate application logic, bypass security controls, or cause erratic behavior by injecting prototype pollution payloads. This can lead to compromised application workflows, data corruption, or indirect privilege escalation if the polluted prototype affects security-critical code paths. Organizations in sectors such as finance, healthcare, and critical infrastructure that rely on Node.js-based services or microservices parsing YAML configurations or data are particularly at risk. The medium severity rating reflects that while confidentiality and availability are not directly impacted, the integrity compromise can have cascading effects on trustworthiness and operational correctness. Given the widespread use of js-yaml in the JavaScript ecosystem, the scope of affected systems is broad, increasing the potential attack surface. The lack of required authentication and user interaction further elevates the risk, especially for publicly accessible services.

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

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Jan 2026, 08:08 UTC

WeaknessesCWE-1321

Technical details

References

Community reviews

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