CVE-2026-19671
mediumpriority · track · 0OT risk · elevatedEPSS 0.004 · 38 %ileUSEPSS · scored 2026-10-28
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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedMalcolmcisa_csaf_ot
Malcolm version 26.08.0 addresses this issue. For more information, see https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6. (CVE-2026-19671)
https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.9–7.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
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affected products (2)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- ICSA-26-230-01CISA Malcolm2026-08-18icsa · cisa_csaf_otUS
Successful exploitation of these vulnerabilities could allow an attacker to cause a denial-of-service condition or execute arbitrary code.
- CVE-2026-19670Incorrect Authorization in CISA Malcolm2026-08-18vendor · osvUS
Malcolm's nginx Lua role-based access control (RBAC) layer decides whether an authenticated user may reach a role-restricted path (e.g. /htadmin, /auth, /admin_login, /arkime/api/esadmin, NetBox, upload endpoints) by pattern-matching the raw, percent-encoded request URI. Nginx itself, however, selects which location block actually serves the request using the percent-decoded, normalized URI. Because the RBAC check never percent-decodes its input, an authenticated low-privilege user can request an admin-only path using percent-encoding (e.g. /%68tadmin.php) and have nginx route it to the restricted location while the Lua RBAC gate evaluating the un-decoded raw string finds no matching restriction and grants access.
also known as (1)
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sources
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references (2) nvd
External citations — patches, advisories, analysis.
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