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

CISAgov Malcolm · CVE-2026-19671
0 news outlets0 CERTs and agencies0 research labs

Assessment: Track

SSVC decision points: exploitation poc, automatable no, technical impact partial, deployment low.

What is it?

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.

Evidence

No coverage recorded yet.

Exploitation

  • Exploit code published (not verified by us)
  • Exploited in the wild (confirmed by a source)
  • Listed as known exploited (CISA KEV)
CVSS
6.5
EPSS
–
First seen
18 Aug 2026
Status
corroborated

All CISAgov vulnerabilities