GHSA-mh29-5h37-fv8m

    Dashboard / Vulnerabilities / GHSA-mh29-5h37-fv8m

    GHSA-mh29-5h37-fv8m

    Published: 14 Nov 2025Last Modified: 10 Sept 2026

    Summary: js-yaml has prototype pollution in merge (<<)

    Details: ### Impact In js-yaml 4.1.0, 4.0.0, and 3.14.1 and below, 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. ### Patches Problem is patched in js-yaml 4.1.1 and 3.14.2. ### Workarounds You 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). ### References https://cheatsheetseries.owasp.org/cheatsheets/Prototype_Pollution_Prevention_Cheat_Sheet.html

    References: https://github.com/nodeca/js-yaml/security/advisories/GHSA-mh29-5h37-fv8m, https://nvd.nist.gov/vuln/detail/CVE-2025-64718, https://github.com/nodeca/js-yaml/issues/730#issuecomment-3549635876, https://github.com/nodeca/js-yaml/commit/383665ff4248ec2192d1274e934462bb30426879, https://github.com/nodeca/js-yaml/commit/5278870a17454fe8621dbd8c445c412529525266, https://github.com/advisories/GHSA-mh29-5h37-fv8m, https://github.com/nodeca/js-yaml

    Affected packages

    Package

    Name: js-yaml

    Purl: pkg:npm/js-yaml

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 4.0.0
    Fixed -4.1.1

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    GHSA-mh29-5h37-fv8m | CVE-DB