CVE-2026-59880

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 78% 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
Trending — 4 sources updated this weekElevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 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)
EPSS
21.9%
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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 13× 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. 2026-07-11 15:44 UTCEG score recompute
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-11 03:45 UTCEG score recompute▼ 1.20
  5. 2026-07-10 20:19 UTCNVD updateCVSS v3 → 7.5
  6. 2026-07-10 15:46 UTCEG score recompute
  7. 2026-07-10 03:46 UTCEG score recompute
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-09 19:10 UTCEPSS rescore
  10. 2026-07-09 15:46 UTCEG score recompute
  11. 2026-07-09 03:45 UTCEG score recompute
  12. 2026-07-08 15:46 UTCEG score recompute
  13. 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 21.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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.

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