Medium severity · published Oct 8, 2026
CVE-2026-107335
Improper Handling of Highly Compressed Data in Malcolm
6.5
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Malcolm · CISA
through 26.07.1 · source: vendor
In the news
VulnerabilityHigh
CISA Malcolm
View CSAF
Summary
The following versions of CISA Malcolm are affected:
Malcolm <=v26.07.1 (CVE-2026-107336, CVE-2026-107361, CVE-2026-107337, CVE-2026-107335, CVE-2026-107334)
Malcolm <=v26.08.0 (CVE-2026-107333, CVE-2026-107362)
CVSS
Vendor
Equipment
v3 8.1
CISA
Malcolm
6 Vulnerabilities
Authentication Bypass by Spoofing, Incorrect Authorization, Server-Side Request Forgery (SSRF), Authentication Bypass Using an Alternate Path or Channel, Cross-Site Request Forgery (CSRF), Improper Handling of Highly Compressed Data (Data Amplification)
Background
Critical Infrastructure Sectors: Energy, Information Technology, Water and Wastewater Systems
Countries/Areas Deployed: Worldwide
Company Headquarters Location: United States
Vulnerabilities
Expand All +
CVE-2026-107336
Malcolm's front nginx reverse proxy defines a "Dashboards → Arkime shortcut" location using a case-insensitive regex matcher but a case-sensitive rewrite. A request whose path segment is not exact-lowercase (for example /IDDASH2ARK/...) enters the location (the matcher fires) but evades the rewrite (no redirect is issued), so nginx falls through to the location's proxy_pass to the Arkime backend. That location is the one proxied location in the shipped config that does not include the per-location authentication file, so the request reaches Arkime unauthenticated. The same location also forwards a client-s...
Oct 15, 2026·CISA Advisories
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-107335
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-107335
github.com
https://github.com/cisagov/Malcolm/security/advisories/GHSA-f2v6-8cj4-mhr6
government-resource
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-280-01.json
More from Malcolm
8.8
CVE-2026-90444
OS Command Injection in Malcolm
8.1
CVE-2026-107333
Incorrect Authorization in Malcolm
8.1
CVE-2026-90456
Use of default credentials in Malcolm
7.1
CVE-2026-107337
Cross-Site Request Forgery in Malcolm
7.1
CVE-2026-107362
Server-Side Request Forgery in Malcolm
