CVE-2026-107335
Received Received - Intake

Denial of Service in Malcolm Upload Pipeline via Compressed File

Publication date: 2026-10-08

Last updated on: 2026-10-08

Assigner: ICS-CERT

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.

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Meta Information

Published
2026-10-08
Last Modified
2026-10-08
Generated
2026-10-08
AI Q&A
2026-10-08
EPSS Evaluated
N/A
NVD
CVE-2026-107335
EUVD
EUVD-2026-95122

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
CISA Malcolm 0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-409 The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

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Executive Summary

This vulnerability involves Malcolm's upload-processing pipeline not enforcing size limits when extracting single-stream compressed files like .gz or .bz2. An attacker can upload a small, highly compressible file that decompresses to an extremely large size, consuming all available disk space in the shared Docker volume used by multiple security tools.

Detection Guidance

Monitor disk usage on the shared Docker volume where Malcolm processes files. Check for unusually large decompressed files from small compressed uploads, especially .gz, .bz2, .xz, .lzma, or .lz formats.

Impact Analysis

If exploited, this vulnerability can cause a denial-of-service by filling up the shared Docker volume. This disrupts all users and services relying on the platform, including OpenSearch, Logstash, Arkime, and Zeek, leading to service outages and potential data loss.

Mitigation Strategies

Apply the same entry-count, nesting-depth, and total-uncompressed-byte limits to single-stream compressed formats (.gz, .bz2, etc.) in the upload-processing pipeline. Restrict authenticated upload permissions to trusted users only.

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