Inefficient Algorithmic Complexity Affecting openssl package, versions [3.4.0,3.4.8)[3.5.0,3.5.9)[3.6.0,3.6.5)[4.0.1,4.0.3)
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-CONAN-OPENSSL-20537036
- published6 Oct 2026
- disclosed29 Sept 2026
- creditSaku0512,Opal Wright
Introduced: 29 Sep 2026
NewCVE-2026-42772 (opens in a new tab)How to fix?
Upgrade openssl to version 3.4.8, 3.5.9, 3.6.5, 4.0.3 or higher.
Overview
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the QUIC stream reassembly, which holds fragments in a doubly linked list optimized for appends and searches it head to tail when a fragment arrives out of order. An attacker can consume CPU quadratically in the number of fragments by ordering stream frame offsets so each one requires a full traversal. This requires a completed handshake, the frames are protocol compliant and need little bandwidth, and the pressure is scoped to that connection.