CVE-2026-59880

HIGHNVD 7.57.5
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, Immutable.Map and Immutable.Set keep keys that share the same 32-bit hash in a HashCollisionNode collision bucket that is scanned linearly, allowing an attacker who controls keys inserted into a Map, such as through Immutable.Map(obj), Immutable.fromJS(obj), state.merge(userObject), or mergeDeep, to craft many colliding keys and degrade insertion and lookup to consume disproportionate CPU. This issue is fixed in versions 4.3.9 and 5.1.8.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 10, 2026

Advisory Details (5)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Hash-collision algorithmic complexity denial of service in Immutable.Map/Set · Advisory · immutable-js/immutable-js · GitHub

https://github.com/immutable-js/immutable-js/security/advisories/GHSA-xvcm-6775-5m9r
github_release Patch Available

v5.1.8

Patch available: immutable-js/immutable-js v5.1.8

https://github.com/immutable-js/immutable-js/releases/tag/v5.1.8
github_release Patch Available

v4.3.9

Patch available: immutable-js/immutable-js v4.3.9

https://github.com/immutable-js/immutable-js/releases/tag/v4.3.9
github_commit Patch Available

commit e51d49fc612d (immutable-js/immutable-js)

Patch available: immutable-js/immutable-js v5.1.8 (contains commit e51d49fc612d)

https://github.com/immutable-js/immutable-js/commit/e51d49fc612ded5ec4dfb94ff294d22074269b0f
github_commit Patch Available

commit 3dd7e5655012 (immutable-js/immutable-js)

Patch available: immutable-js/immutable-js v4.3.9 (contains commit 3dd7e5655012)

https://github.com/immutable-js/immutable-js/commit/3dd7e5655012597a41873e328bf9142a8901527b

Vendor Advisories for CVE-2026-59880(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
immutable5.1.8

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 16× in last 7d / 36× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-27 00:30 UTCEG score recompute
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 12:27 UTCEG score recompute
  5. 2026-07-25 14:18 UTCEPSS rescore
  6. 2026-07-25 14:18 UTCEPSS rescore
  7. 2026-07-24 14:18 UTCEPSS rescore
  8. 2026-07-24 14:18 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 14:18 UTCEPSS rescore
  11. 2026-07-23 03:21 UTCEG score recompute
  12. 2026-07-22 14:08 UTCEPSS rescore
  13. 2026-07-22 14:08 UTCEPSS rescore
  14. 2026-07-21 15:25 UTCEPSS rescore
  15. 2026-07-21 15:25 UTCEPSS rescore
  16. 2026-07-20 17:08 UTCEPSS rescore
  17. 2026-07-19 14:31 UTCEPSS rescore
  18. 2026-07-19 02:29 UTCEPSS rescore
  19. 2026-07-18 10:04 UTCEPSS rescore
  20. 2026-07-16 17:03 UTCEPSS rescore
  21. 2026-07-15 16:57 UTCEPSS rescore
  22. 2026-07-15 16:57 UTCEPSS rescore
  23. 2026-07-15 02:00 UTCEPSS rescore
  24. 2026-07-15 02:00 UTCEPSS rescore
  25. 2026-07-13 22:31 UTCEPSS rescore
Show 11 more
  1. 2026-07-13 06:13 UTCEPSS rescore
  2. 2026-07-13 06:13 UTCEPSS rescore
  3. 2026-07-12 05:46 UTCEPSS rescore
  4. 2026-07-11 08:27 UTCEPSS rescore
  5. 2026-07-11 08:27 UTCEPSS rescore
  6. 2026-07-11 03:45 UTCEG score recompute 1.20
  7. 2026-07-10 20:19 UTCNVD updateCVSS v3 → 7.5
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-09 19:10 UTCEPSS rescore
  10. 2026-07-08 15:46 UTCEG score recompute
  11. 2026-07-08 15:45 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-59880?
CVE-2026-59880 is a high vulnerability published on July 8, 2026. Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, Immutable.Map and Immutable.Set keep keys that share the same 32-bit hash in a HashCollisionNode collision bucket that is scanned linearly, allowing an attacker who controls keys inserted into a Map, such as…
When was CVE-2026-59880 disclosed?
CVE-2026-59880 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59880 actively exploited?
CVE-2026-59880 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 64.6% of all scored CVEs.
What is the CVSS score of CVE-2026-59880?
CVE-2026-59880 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-59880?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59880, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-59880

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Is Your Infrastructure Affected by CVE-2026-59880?

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