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Full vulnerability report · 2026
CVE-2026-59880High confidence

Immutable.js: Hash-collision algorithmic complexity denial of service in Immutable.Map/Set

immutable-js · immutable-js

Official source article: GitHub GHSA-XVCM-6775-5M9R ↗. Check the applicable product and release in the original source.

8.7HighCVSS 4.0
Recommended action
Patch only the product branches with a verified fix

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 8 Jul 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.66% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs immutable-js immutable-js and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

5 package states
Package result overrides the generic status

BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 2 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcenode-immutableAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcenode-immutableAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcenode-immutableVendor fix publishedDebian records a fixed source-package version for this release.4.3.9-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcenode-immutableVendor fix publishedDebian records a fixed source-package version for this release.4.3.9-1Debian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivenode-immutableUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Open-source package ranges6 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
npmimmutable>= 5.0.0-beta.1, < 5.1.85.1.8GitHub advisory ↗upstream repository advisory · 3 Sep 2026
npmimmutable>= 4.0.0-beta.1, < 4.3.94.3.9GitHub advisory ↗upstream repository advisory · 3 Sep 2026
npmimmutable< 3.8.43.8.4GitHub advisory ↗upstream repository advisory · 3 Sep 2026
npmimmutableSEMVER: introduced 4.0.0-beta.1; fixed 4.3.94.3.9OSV record ↗aggregator derived · 10 Sep 2026
npmimmutableSEMVER: introduced 5.0.0-beta.1; fixed 5.1.85.1.8OSV record ↗aggregator derived · 10 Sep 2026
npmimmutableSEMVER: introduced 0; fixed 3.8.43.8.4OSV record ↗aggregator derived · 10 Sep 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-42315

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

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.

What

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.

Why

An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Inefficient Algorithmic Complexity → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-407 ↗

CWE-407: Inefficient Algorithmic Complexity. An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-407Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-3623IBM DataPower Gateway: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM DataPower Gateway ausnutzen, um beliebigen Programmcode auszuführen, erweiterte Berechtigungen zu erlangen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen, einen Denial-of-Service-Zustand auszulösen oder Cross-Site-Scripting-Angriffe durchzuführen.

Official advisory ↗
BSI · German · WID-SEC-2026-3376Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsmaßnahmen zu umgehen, serverseitige Request-Forgery-Angriffe (SSRF) durchzuführen, Cross-Site-Scripting-Angriffe zu starten, sensible Informationen offenzulegen, Daten zu manipulieren oder Denial-of-Service-Zustände herbeizuführen.

Official advisory ↗
BSI · German · WID-SEC-2026-2636IBM Tivoli Netcool/OMNIbus (Immutable.js): Mehrere Schwachstellen ermöglichen Denial of Service

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in IBM Tivoli Netcool/OMNIbus ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1256Multiples vulnérabilités dans les produits IBM

d?id=CVE-2026-59848 Référence CVE CVE-2026-59850 https://www.cve.org/CVERecord?id=CVE-2026-59850 Référence CVE CVE-2026-59869 https://www.cve.org/CVERecord?id=CVE-2026-59869 Référence CVE CVE-2026-59871 https://www.cve.org/CVERecord?id=CVE-2026-59871 Référence CVE CVE-2026-59873 https://www.cve.org/CVERecord?id=CVE-2026-59873 Référence CVE CVE-2026-59874 https://www.cve.org/CVERecord?id=CVE-2026-59874 Référence CVE CVE-2026-59875 https://www.cve.org/CVERecord?id=CVE-2026-59875 Référence CVE CVE-2026-59878 https://www.cve.org/CVERecord?id=CVE-2026-59878 Référence CVE CVE-2026-59879 https://www.cve.org/CVERecord?id=CVE-2026-59879 Référence CVE CVE-2026-59880 https://www.cve.org/CVERecord?id=CVE-2026-59880 Référence CVE CVE-2026-59887 https://www.cve.org/CVERecord?id=CVE-2026-59887 Référence CVE CVE-2026-59888 https://www.cve.org/CVERecord?id=CVE-2026-59888 Référence CVE CVE-2026-59889 https://www.cve.org/CVERecord?id=CVE-2026-59889 Référence CVE CVE-2026-59949 https://www.cve.org/CVERecord?id=CVE-2026-59949 Référence CVE CVE-2026-60589 https://www.cve.org/CVERecord?id=CVE-2026-60589 Référence CVE CVE-2026-61308 https://www.cve.org/CVERecord?id=CVE-2026-61308 Référence CVE CVE-2026-61487 https://www.cve.org/CVERecord?id=CVE-2026-61487 Référence CVE CVE-2026-63072 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1165Multiples vulnérabilités dans les produits IBM

d?id=CVE-2026-59642 Référence CVE CVE-2026-59645 https://www.cve.org/CVERecord?id=CVE-2026-59645 Référence CVE CVE-2026-59647 https://www.cve.org/CVERecord?id=CVE-2026-59647 Référence CVE CVE-2026-59648 https://www.cve.org/CVERecord?id=CVE-2026-59648 Référence CVE CVE-2026-59650 https://www.cve.org/CVERecord?id=CVE-2026-59650 Référence CVE CVE-2026-59651 https://www.cve.org/CVERecord?id=CVE-2026-59651 Référence CVE CVE-2026-59652 https://www.cve.org/CVERecord?id=CVE-2026-59652 Référence CVE CVE-2026-59869 https://www.cve.org/CVERecord?id=CVE-2026-59869 Référence CVE CVE-2026-59879 https://www.cve.org/CVERecord?id=CVE-2026-59879 Référence CVE CVE-2026-59880 https://www.cve.org/CVERecord?id=CVE-2026-59880 Référence CVE CVE-2026-59888 https://www.cve.org/CVERecord?id=CVE-2026-59888 Référence CVE CVE-2026-59889 https://www.cve.org/CVERecord?id=CVE-2026-59889 Référence CVE CVE-2026-59893 https://www.cve.org/CVERecord?id=CVE-2026-59893 Référence CVE CVE-2026-59894 https://www.cve.org/CVERecord?id=CVE-2026-59894 Référence CVE CVE-2026-59898 https://www.cve.org/CVERecord?id=CVE-2026-59898 Référence CVE CVE-2026-59899 https://www.cve.org/CVERecord?id=CVE-2026-59899 Référence CVE CVE-2026-59901 https://www.cve.org/CVERecord?id=CVE-2026-59901 Référence CVE CVE-2026-59903 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1094Multiples vulnérabilités dans les produits IBM

ord?id=CVE-2026-59204 Référence CVE CVE-2026-59205 https://www.cve.org/CVERecord?id=CVE-2026-59205 Référence CVE CVE-2026-5928 https://www.cve.org/CVERecord?id=CVE-2026-5928 Référence CVE CVE-2026-59724 https://www.cve.org/CVERecord?id=CVE-2026-59724 Référence CVE CVE-2026-59725 https://www.cve.org/CVERecord?id=CVE-2026-59725 Référence CVE CVE-2026-59858 https://www.cve.org/CVERecord?id=CVE-2026-59858 Référence CVE CVE-2026-59869 https://www.cve.org/CVERecord?id=CVE-2026-59869 Référence CVE CVE-2026-59877 https://www.cve.org/CVERecord?id=CVE-2026-59877 Référence CVE CVE-2026-59879 https://www.cve.org/CVERecord?id=CVE-2026-59879 Référence CVE CVE-2026-59880 https://www.cve.org/CVERecord?id=CVE-2026-59880 Référence CVE CVE-2026-59887 https://www.cve.org/CVERecord?id=CVE-2026-59887 Référence CVE CVE-2026-59888 https://www.cve.org/CVERecord?id=CVE-2026-59888 Référence CVE CVE-2026-59890 https://www.cve.org/CVERecord?id=CVE-2026-59890 Référence CVE CVE-2026-60081 https://www.cve.org/CVERecord?id=CVE-2026-60081 Référence CVE CVE-2026-60147 https://www.cve.org/CVERecord?id=CVE-2026-60147 Référence CVE CVE-2026-6238 https://www.cve.org/CVERecord?id=CVE-2026-6238 Référence CVE CVE-2026-62389 https://www.cve.org/CVERecord?id=CVE-2026-62389 Référence CVE CVE-2026-6321 https://www.cve.org/CVERecord?id=CVE

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1067Multiples vulnérabilités dans les produits IBM

d?id=CVE-2026-47244 Référence CVE CVE-2026-48043 https://www.cve.org/CVERecord?id=CVE-2026-48043 Référence CVE CVE-2026-48959 https://www.cve.org/CVERecord?id=CVE-2026-48959 Référence CVE CVE-2026-48962 https://www.cve.org/CVERecord?id=CVE-2026-48962 Référence CVE CVE-2026-50560 https://www.cve.org/CVERecord?id=CVE-2026-50560 Référence CVE CVE-2026-50645 https://www.cve.org/CVERecord?id=CVE-2026-50645 Référence CVE CVE-2026-54225 https://www.cve.org/CVERecord?id=CVE-2026-54225 Référence CVE CVE-2026-57819 https://www.cve.org/CVERecord?id=CVE-2026-57819 Référence CVE CVE-2026-59879 https://www.cve.org/CVERecord?id=CVE-2026-59879 Référence CVE CVE-2026-59880 https://www.cve.org/CVERecord?id=CVE-2026-59880 Référence CVE CVE-2026-59995 https://www.cve.org/CVERecord?id=CVE-2026-59995 Référence CVE CVE-2026-59996 https://www.cve.org/CVERecord?id=CVE-2026-59996 Référence CVE CVE-2026-59997 https://www.cve.org/CVERecord?id=CVE-2026-59997 Référence CVE CVE-2026-59999 https://www.cve.org/CVERecord?id=CVE-2026-59999 Référence CVE CVE-2026-60000 https://www.cve.org/CVERecord?id=CVE-2026-60000 Référence CVE CVE-2026-60001 https://www.cve.org/CVERecord?id=CVE-2026-60001 Référence CVE CVE-2026-60002 https://www.cve.org/CVERecord?id=CVE-2026-60002 Référence CVE CVE-2026-60147 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-023244Immutable-jsのImmutableにおけるアルゴリズムの複雑さに関する脆弱性

Immutable.jsは多くの永続的な不変データ構造を提供しています。バージョン4.3.9および5.1.8より前のImmutable.MapおよびImmutable.Setは、同じ32ビットハッシュを共有するキーをHashCollisionNodeの衝突バケットに保持し、それを線形にスキャンします。このため、Immutable.Map(obj)、Immutable.fromJS(obj)、state.merge(userObject)、またはmergeDeepなどを通じてMapに挿入されるキーを攻撃者が制御できる場合には、多数の衝突するキーを作成し、挿入および検索処理のパフォーマンスを劣化させて過剰なCPU使用を引き起こすことが可能です。この問題はバージョン4.3.9および5.1.8で修正されています。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
immutable-js: < 4.3.9, >= 5.0.0-beta.1, < 5.1.8
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
Official vendor articles1 stored document

Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.

04

Evidence and provenance

Published 8 Jul 2026 · Last source change 8 Jul 2026, 16:13 UTC · CWE-407 · Inefficient Algorithmic Complexity

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-42315
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-59880 · cve.blacktree.nl