CVE-2026-83621: Auth Bypass (CVSS 8.1)

Description

ntopng is a web-based network traffic monitoring application. Prior to 6.7.260717, POST /lua/rest/v2/edit/system/edit_blacklist.lua in scripts/lua/rest/v2/edit/system/edit_blacklist.lua lacks an administrator check and calls lists_utils.editList for any authenticated user. The list_name, list_enabled, url, and list_update parameters allow a non-admin user to redirect threat-intelligence downloads to attacker-controlled content, disable blocklists, or prevent scheduled updates. The changes are persisted through Redis and reloaded without a lower-level authorization guard, undermining the integrity and availability of ntopng's threat-intelligence monitoring. This issue is fixed in version 6.7.260717.

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CVSS v3.1 Score

8.1

HIGH

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

EPSS — Exploit Prediction

0.0053

Probability of exploitation

0.43%

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-862 Missing Authorization

References

Other References

https://github.com/ntop/ntopng/commit/1d0627d802c59130c82478a4eb7f14014064eae5 https://github.com/ntop/ntopng/commit/669589fe208fc932fe40a840e0de8e4d9df6023f https://github.com/ntop/ntopng/security/advisories/GHSA-ffg5-889g-f5q8

Frequently Asked Questions

What is CVE-2026-83621? +

ntopng is a web-based network traffic monitoring application. Prior to 6.7.260717, POST /lua/rest/v2/edit/system/edit_blacklist.lua in scripts/lua/rest/v2/edit/system/edit_blacklist.lua lacks an administrator check and calls lists_utils.editList for any authenticated user. The list_name, list_enabled, url, and list_update parameters allow a non-admin user to redirect threat-intelligence downloads to attacker-controlled content, disable blocklists, or prevent scheduled updates. The changes are persisted through Redis and reloaded without a lower-level authorization guard, undermining the integrity and availability of ntopng's threat-intelligence monitoring. This issue is fixed in version 6.7.260717. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-83621? +

CVE-2026-83621 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0053, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-83621? +

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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