Inefficient Algorithmic Complexity Affecting immutable package, versions <4.3.9>=5.0.0-beta.1 <5.1.8
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-IMMUTABLE-17900558
- published9 Jul 2026
- disclosed8 Jul 2026
- creditnvth
Introduced: 8 Jul 2026
NewCVE-2026-59880 (opens in a new tab)How to fix?
Upgrade immutable to version 4.3.9, 5.1.8 or higher.
Overview
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity via the HashCollisionNode class in Immutable.Map and Immutable.Set. An attacker can cause excessive CPU consumption by supplying a large number of keys with identical 32-bit hashes, leading to degraded insertion and lookup performance through crafted input objects.