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NVD / CVE Program· CNA GitHub_M

CVE-2026-29063: Immutable.js: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in immutable

Noroxi assessment

Priority: Monitor (action score 34/100)

  • 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: 1% (FIRST EPSS); higher than 63.2% of all records.
  • 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-immutable (Debian:14) 4.3.8-1; immutable (npm) 4.3.8, 5.1.5, 3.8.3.

Low priority for now. Upgrade to node-immutable (Debian:14) 4.3.8-1; immutable (npm) 4.3.8, 5.1.5, 3.8.3 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

Immutable.js provides many Persistent Immutable data structures. Prior to versions 3.8.3, 4.3.7, and 5.1.5, Prototype Pollution is possible in immutable via the mergeDeep(), mergeDeepWith(), merge(), Map.toJS(), and Map.toObject() APIs. This issue has been patched in versions 3.8.3, 4.3.7, and 5.1.5.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Mar 6, 2026
Updated
Oct 30, 2026
EPSS
1.0% · 63th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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-2026-29063

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
immutable-jsimmutable
redhat3scale api management platform
redhatadvanced cluster management for kubernetes
redhatadvanced cluster security
redhatansible automation platform
redhatbuild of apicurio registry
redhatconnectivity link
redhatdeveloper hub
redhatdiscovery
redhatedge manager
redhatlogging subsystem for red hat openshift
redhatmigration toolkit

and 15 more

Affected versions

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

  • immutable-js immutable4.0.0 and later · before 4.3.8
  • immutable-js immutable3.0.0 and later · before 3.8.3
  • immutable-js immutable5.0.0 and later · before 5.1.5
  • redhat 3scale api management platform2.0
  • redhat advanced cluster management for kubernetes2.14 and later · before 2.14.3
  • redhat advanced cluster management for kubernetes2.15 and later · before 2.15.2
  • redhat advanced cluster management for kubernetes2.16 and later · before 2.16.1
  • redhat advanced cluster security4.8.0 and later · before 4.8.11
  • redhat advanced cluster security4.9.0 and later · before 4.9.6
  • redhat advanced cluster security4.10.0 and later · before 4.10.2
  • redhat ansible automation platform2.0
  • redhat build of apicurio registry2.0
  • redhat connectivity link1.0
  • redhat developer hub1.8.0 and later · before 1.8.6
  • redhat developer hub1.9.0 and later · before 1.9.4
  • redhat discovery2.0
  • redhat edge manager1.0 and later · before 1.0.3
  • redhat edge manager1.1 and later · before 1.1.3
  • redhat enterprise linux10.0
  • redhat enterprise linux8.0

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.

  • immutable-js immutable-js

    • < 3.8.3, < 4.3.7, < 5.1.5affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12node-immutablefrom 0—
Debian:14node-immutablebefore 4.3.8-14.3.8-1
npmimmutablefrom 4.0.0-rc.1 · before 4.3.84.3.8
npmimmutablefrom 5.0.0 · before 5.1.55.1.5
npmimmutablebefore 3.8.33.8.3

Same product

immutable-js: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-59879Immutable.js `List` 32-bit trie overflow → unrecoverable DoS
    34Monitor
  • CVE-2026-59880Immutable.js: Hash-collision algorithmic complexity denial of service in Immutable.Map/Set
    34Monitor

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-immutable4.3.8-1 · Debian:14Package registry (OSV)
npm:immutable3.8.3Package registry (OSV)
npm:immutable4.3.8Package registry (OSV)
npm:immutable5.1.5Package 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.

No commit or PR link among the references.

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
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

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

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 (19 more)

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

All records