CVE-2026-91002: Auth Bypass (CVSS 5.3)

Description

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.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0044

Probability of exploitation

0.38%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-287 Improper Authentication

CWE-306 Missing Authentication

References

Other References

https://gist.github.com/simyat/fd48e9c257ab95405c109aec575977f1 https://github.com/stamparm/maltrail/ https://github.com/stamparm/maltrail/commit/d95868dff3da4d3bd4f942837a26cb7c73a797ae https://github.com/stamparm/maltrail/releases/tag/3.1 https://vuldb.com/cve/CVE-2026-91002 https://vuldb.com/submit/931699 https://vuldb.com/vuln/403583 https://vuldb.com/vuln/403583/cti

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-91002? +

CVE-2026-91002 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0044, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-91002? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-91002