Vulnerability in immutable (CVE-2026-59880)
Summary
Vulnerability in immutable (CVE-2026-59880). Risk of unauthorized operations or information disclosure. Exploitable via Immutable.Map. Mitigation: upgrade to 5.1.8 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59880 has been found in immutable.
Attackers can target a specific entry point like Immutable.Map over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade immutable to 5.1.8 or later.
If unsure, ask your IT team or search "immutable CVE-2026-59880" on the vendor's site.
CVE-2026-59880 (immutable) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Immutable.Map / Immutable.Set / HashCollisionNode / get
Patched: 5.1.8 — apply immediately
Workaround: Before passing untrusted data to Immutable.js: cap request body size, limit object key count/length, and reject high-cardinality payloads; avoid building Maps directly from untrusted object keys.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in immutable. Attackers reach the vulnerable code path via Immutable.Map without authentication.
Check the vendor advisory for the affected versions of immutable. Attack surface: Immutable.Map / Immutable.Set / HashCollisionNode / get.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 5.1.8.
Workaround: Before passing untrusted data to Immutable.js: cap request body size, limit object key count/length, and reject high-cardinality payloads; avoid building Maps directly from untrusted object keys.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'immutable' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'immutable' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
immutableを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Before passing untrusted data to Immutable.js: cap request body size, limit object key count/length, and reject high-cardinality payloads; avoid building Maps directly from untrusted object keys.パッチが適用されるまでの応急処置として、Before passing untrusted data to Immutable.js: cap request body size, limit object key count/length, and reject high-cardinality payloads; avoid building Maps directly from untrusted object keys. を実施。回避策の副作用 (機能低下) を確認した上で。
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3Apply patch patch
Upgrade immutable to 5.1.8ステージング環境で 5.1.8 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-59880 node-immutable
- Ubuntu UBUNTU-CVE-2026-59880 node-immutable
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- ATLASSIAN JSWSERVER-26895
- patch github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web github.com