---
id: CVE-2020-28873
title: >-
  Fluxbb 1.5.11 is affected by a denial of service (DoS) vulnerability by
  sending an extremely long password via the user login form
summary: >-
  Fluxbb 1.5.11 is affected by a denial of service (DoS) vulnerability by
  sending an extremely long password via the user login form. When a long
  password is sent, the password hashing process will result in CPU and memory
  exhaustion on th…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-916
vendor: fluxbb
product: fluxbb
affected:
  - fluxbb = 1.5.11
published: '2021-03-17'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-28873'
references:
  - url: >-
      https://www.acunetix.com/vulnerabilities/web/long-password-denial-of-service/#:~:text=By%20sending%20a%20very%20long%2Ca%20vulnerable%20password%20hashing%20implementation
    label: cve@mitre.org
  - url: 'http://fluxbb.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.acunetix.com/vulnerabilities/web/long-password-denial-of-service/#:~:text=By%20sending%20a%20very%20long%2Ca%20vulnerable%20password%20hashing%20implementation
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00858
epssPercentile: 0.56699
ingestedAt: '2026-07-05T00:59:25.839Z'
---

## Overview

Fluxbb 1.5.11 is affected by a denial of service (DoS) vulnerability by sending an extremely long password via the user login form. When a long password is sent, the password hashing process will result in CPU and memory exhaustion on the server.

## Affected

- `fluxbb = 1.5.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.