9.8

CVE-2026-29063: immutable-js immutable Prototype Pollution

CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2026-29063DEBIAN-CVE-2026-29063CGA-235c-fr86-p22q
Published 06-03-2026Last modified 10-09-2026
Open JSON

Vulnerability summary

CVE-2026-29063 is a critical (CVSS 9.8) Prototype Pollution vulnerability in immutable-js immutable. EPSS estimates a 1.61% chance of exploitation in the next 30 days, higher than 75.5% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
1.61%
0%100%
Low · +0.63 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-8CFG-6HVQ-2RC7

Timeline

  1. 06-03-2026
    PublishedVulnerability first disclosed.
  2. 10-09-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

11 scores · 7 sources · 2 versions

EPSS trend

Probability

1.61%

Chance of exploitation in the next 30 days

Percentile

76%

Versus all other CVEs

30-day change

+0.63 pp

From 0.98% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.61%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Immutable Js

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Chainguard45 products
  • arangodb-3.11< 3.11.14.5-r13
  • arangodb-3.12< 3.12.9.4-r26
  • argo-workflows-ui-3.6< 3.6.19-r3
  • argo-workflows-ui-3.7< 3.7.10-r4
  • argo-workflows-ui-4.0< 4.0.1-r4
Wolfi14 products
  • argo-workflows-ui-3.7< 3.7.10-r4
  • argo-workflows-ui-4.0< 4.0.1-r4
  • katib-earlystopping< 0.19.0-r31
  • katib-suggestion-goptuna-compatAll versions (No fix recorded)
  • katib-suggestion-hyperband< 0.19.0-r31
Immutable-js2 products
  • immutable≥ 3.0.0, < 3.8.3 | ≥ 4.0.0, < 4.3.7 | ≥ 5.0.0, < 5.1.5
  • immutable-js< 3.8.3 | < 4.3.7 | < 5.1.5
Debian1 product
  • node-immutableAll versions (No fix recorded) | < 4.3.8-1
Npm1 product
  • immutable≥ 4.0.0-rc.1, < 4.3.8 | ≥ 5.0.0, < 5.1.5 | < 3.8.3
Ubuntu1 product
  • node-immutableAll versions (No fix recorded)

6 vendors · 64 products

References

82 links
Show all 82 references