Auth bypass in Stamparm Maltrail
CVE-2026-91002
A weakness has been identified in stamparm maltrail up to 3.0.1. This vulnerability affects the function _blacklist of the file core/httpd.py of the component Blacklist Endpoint. Executing a manipulation can lead to missing authentication. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 3.1 is able to resolve this issue. This patch is called d95868dff3da4d3bd4f942837a26cb7c73a797ae. It is suggested to upgrade the affected component. The vendor fixed the issue the same day it was reported, in version 3.1, by gating the endpoint on an authenticated session or the new Blacklist_ALLOWLIST option.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.008 (55.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000
Affected products
- Stamparm Maltrail — versions 3.0.0, 3.0.1
Weakness classification (CWE)
References
- vuldb.com/vuln/403583 (technical-description, vdb-entry)
- vuldb.com/vuln/403583/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-91002 (third-party-advisory)
- vuldb.com/submit/931699 (third-party-advisory)
- gist.github.com/simyat/fd48e9c257ab95405c109aec575977f1 (exploit)
- github.com/stamparm/maltrail/commit/d95868dff3da4d3bd4f942837a26cb7c73a797ae (patch)
- github.com/stamparm/maltrail/releases/tag/3.1 (patch)
- github.com/stamparm/maltrail/ (product)
Frequently asked questions
- What is CVE-2026-91002?
- CVE-2026-91002 is a medium-severity vulnerability in Stamparm Maltrail, classified under Improper Authentication. CVSS score: 5.3/10. Published 2026-09-15.
- How severe is CVE-2026-91002?
- Medium severity. CVSS v3 base score is 5.3 out of 10.