Vulnerability in Cisagov Malcolm
CVE-2026-19671
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.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
Weakness classification (CWE)
References
- ics-cert@hq.dhs.gov (government-resource)
- ics-cert@hq.dhs.gov
Frequently asked questions
- What is CVE-2026-19671?
- CVE-2026-19671 is a medium-severity vulnerability in Cisagov Malcolm, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 6.5/10. Published 2026-08-18.
- How severe is CVE-2026-19671?
- Medium severity. CVSS v3 base score is 6.5 out of 10.