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NVD / CVE Program· CNA GitHub_M

CVE-2025-64718: js-yaml has prototype pollution in merge (<<)

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.42% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: node-js-yaml (Debian:14) 4.1.1+dfsg+~4.0.9-1; js-yaml (npm) 4.1.1, 3.14.2; cockpit-repos (openSUSE:Leap 16.0) 4.7-160000.1.1.

Low priority for now. Upgrade to node-js-yaml (Debian:14) 4.1.1+dfsg+~4.0.9-1; js-yaml (npm) 4.1.1, 3.14.2; cockpit-repos (openSUSE:Leap 16.0) 4.7-160000.1.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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).

MediumCVSS 5.3 · v3.1—No exploit Fix available
Published
Nov 13, 2025
Updated
Oct 7, 2026
EPSS
0.4% · 36th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-64718

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nodecajs-yaml

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nodeca js-yamlbefore 3.14.2
  • nodeca js-yaml4.0.0 and later · before 4.1.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • nodeca js-yaml

    • >= 4.0.0, < 4.1.1, < 3.14.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12node-js-yamlfrom 0—
Debian:14node-js-yamlbefore 4.1.1+dfsg+~4.0.9-14.1.1+dfsg+~4.0.9-1
npmjs-yamlfrom 4.0.0 · before 4.1.14.1.1
npmjs-yamlbefore 3.14.23.14.2
openSUSE:Leap 16.0cockpit-reposbefore 4.7-160000.1.14.7-160000.1.1
openSUSE:Leap 16.0cockpit-subscriptionsbefore 12.1-160000.1.112.1-160000.1.1
openSUSE:Tumbleweedcockpit-reposbefore 4.6-1.14.6-1.1
openSUSE:Tumbleweedvelociraptorbefore 0.7.0.4.git185.a5708584-2.10.7.0.4.git185.a5708584-2.1
SUSE:Linux Micro 6.2cockpit-reposbefore 4.7-160000.1.14.7-160000.1.1
SUSE:Linux Micro 6.2cockpit-subscriptionsbefore 12.1-160000.1.112.1-160000.1.1

Same product

nodeca: all records

Other highest-scoring records for the same primary product.

  • CVE-2013-4660The JS-YAML module before 2.0.5 for Node.js parses input without properly considering the unsafe !!js/function tag, which allows remote atta
    40Plan
  • CVE-2026-84375js-yaml: maxTotalMergeKeys does not limit CPU use for empty merge sources
    30Monitor
  • CVE-2026-73643js-yaml: Exponential parsing time in the flow collections leads to denial of service
    30Monitor

Published before and after this one in the same product

  • Later →CVE-2026-53550Jun 22, 2026 · js-yaml: Quadratic-complexity DoS in merge key handling via repeated aliases
    21Monitor
  • Later →CVE-2026-59868Jul 8, 2026 · js-yaml: YAML merge-key chains can force quadratic CPU consumption
    30Monitor
  • Later →CVE-2026-59869Jul 8, 2026 · js-yaml: YAML merge-key chains can force quadratic CPU consumption
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:node-js-yaml4.1.1+dfsg+~4.0.9-1 · Debian:14Package registry (OSV)
npm:js-yaml3.14.2Package registry (OSV)
npm:js-yaml4.1.1Package registry (OSV)
opensuse:cockpit-repos4.6-1.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:cockpit-subscriptions12.1-160000.1.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:velociraptor0.7.0.4.git185.a5708584-2.1 · openSUSE:TumbleweedPackage registry (OSV)
suse:cockpit-repos4.7-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:cockpit-subscriptions12.1-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-1321 · Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records