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Medium · 6.5 CVE-2026-19671 EUVD-2026-61160GHSA-3wrw-4pcx-6p2g

Improper handling of highly compressed data (data amplification) in CISA Malcolm

Published Aug 18, 2026 · Updated Aug 18, 2026 · Assigned by icscert

Description

Malcolm's upload-processing pipeline (scripts/safe-extract.py) enforces entry-count, nesting-depth, and total-uncompressed-byte limits when extracting container archives (zip/tar/rar/7z via libarchive), but those limits are not applied when the uploaded file is a single-stream compressed format (.gz, .bz2, .xz, .lzma, .lz) that isn't a .tar.*-style archive. Any authenticated user permitted to upload PCAP/log files can upload a small, highly compressible file (e.g. a gzip bomb) that decompresses to an effectively unbounded size on disk, exhausting the shared Docker volume used by OpenSearch, Logstash, Arkime, and Zeek, and disrupting the platform for all users.

Affected products

VendorProductAffectedFixed
CISAgov Malcolm ≤ 26.07.1 —

Advisories 1

References