Service interruption via unchecked List bounds
Published Jul 8, 2026 · Updated Jul 8, 2026
Integer overflow in Immutable.js before 4.3.9 and 5.0.0-beta.1 through 5.1.7 allows remote attackers to interrupt applications via large List indexes. setListBounds coerces bounds into signed 32-bit trie arithmetic without first rejecting oversized numeric or numeric-string values, so loops cannot exit or allocation grows until process abort. Exploitation requires a consuming application to pass untrusted input to List mutation APIs; empty lists hang, populated lists exhaust memory, and setSize can silently wrap state.
Summary
What happened
Integer overflow in Immutable.js before 4.3.9 and 5.0.0-beta.1 through 5.1.7 allows remote attackers to interrupt applications via large List indexes. setListBounds coerces bounds into signed 32-bit trie arithmetic without first rejecting oversized numeric or numeric-string values, so loops cannot exit or allocation grows until process abort. Exploitation requires a consuming application to pass untrusted input to List mutation APIs; empty lists hang, populated lists exhaust memory, and setSize can silently wrap state.
The record
- CVE
- CVE-2026-59879
- Published
- Jul 8, 2026
- Updated
- Jul 8, 2026
- Vendor
- Immutable.js
- Product
- Immutable.js
- Classifications
- CWE-1284, CWE-835, CWE-400, CWE-190, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 8, 2026CVE publishedPublication date reported by the CVE source.
- Jul 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.3.9
- Affected versionversion=>= 5.0.0-beta.1, < 5.1.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream List bounds denial-of-service reproductionfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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