Medium severity · published Oct 8, 2026
CVE-2026-107336
Authentication Bypass by Spoofing in Malcolm
6.5
CVSS
0.2%
EPSS
No
On KEV
Description
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-supplied X-Forwarded-User header un-overwritten, and Arkime is configured to trust X-Forwarded-User as the authenticated username — so an unauthenticated network caller can reach the Arkime backend while supplying a forged, auto-provisioned identity.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% 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-2026-107336
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-107336
github.com
https://github.com/cisagov/Malcolm/security/advisories/GHSA-7j32-cf27-cp6h
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
