CVE-2026-90452
Improper certificate validation in Malcolm
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Improper certificate validation in Malcolm
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
- Record
CVE-2026-90452- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2026-76741
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
- Record
EUVD-2026-76741- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-vfcm-4hjc-64rr
Requests from the reverse proxy to the identity-provider service for token discovery,...
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
- Record
GHSA-vfcm-4hjc-64rr- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
NVD
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
- Record
CVE-2026-90452- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSV
Improper certificate validation in Malcolm
Requests from the reverse proxy to the identity-provider service for token discovery, introspection, and credential exchange do not verify the identity provider's server certificate. An attacker positioned on the network path between the proxy and the identity provider could impersonate the identity provider and issue forged authentication tokens accepted by the deployment.
- Record
CVE-2026-90452- CVSS 4.0
- 6.0 Medium
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-295
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-90452 is a medium vulnerability (CVSS 6.0) in Cisa Malcolm, published September 11, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.10%, the 0th percentile. No source names a fixed version.
References
raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json
cisa.gov/news-events/ics-advisories/icsa-26-254-01
nvd.nist.gov/vuln/detail/CVE-2026-90452
github.com/advisories/GHSA-vfcm-4hjc-64rr