---
id: CVE-2026-77582
title: Tinyauth is an authentication and authorization server
summary: >-
  Tinyauth is an authentication and authorization server. Prior to 5.1.0,
  Tinyauth exposes a remotely observable timing difference between
  authentication attempts for existing and nonexistent local usernames.
  internal/controller/user_contr…
severity: medium
cvss: 6.9
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-208
vendor: tinyauthapp
product: tinyauth
affected:
  - tinyauth < 5.1.0
patched:
  - github.com/tinyauthapp/tinyauth 1.0.1-0.20260714134959-c22925c2fba9
published: '2026-09-21'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:15.900'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77582'
references:
  - url: >-
      https://github.com/tinyauthapp/tinyauth/commit/c22925c2fba981875d0a2b09dd3ee41c0ae4c310
    label: security-advisories@github.com
  - url: 'https://github.com/tinyauthapp/tinyauth/pull/1004'
    label: security-advisories@github.com
  - url: 'https://github.com/tinyauthapp/tinyauth/releases/tag/v5.1.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-456h-ww26-f758
    label: security-advisories@github.com
  - url: >-
      https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-456h-ww26-f758
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77582'
  - url: 'https://github.com/advisories/GHSA-456h-ww26-f758'
  - url: 'https://github.com/tinyauthapp/tinyauth'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - go
  - osv
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T19:16:31.589447Z'
cvssSource: cna
epss: 0.00481
epssPercentile: 0.38838
aliases:
  - GHSA-456h-ww26-f758
ecosystem: go
ingestedAt: '2026-09-21T16:49:07.865Z'
---

## Overview

Tinyauth is an authentication and authorization server. Prior to 5.1.0, Tinyauth exposes a remotely observable timing difference between authentication attempts for existing and nonexistent local usernames. internal/controller/user_controller.go loginHandler and internal/middleware/context_middleware.go basicAuth return quickly after internal/service/auth_service.go reports a missing user, while an existing user causes bcrypt password verification work. Repeated measurements can therefore disclose valid usernames and support targeted credential attacks. This issue is fixed in version 5.1.0.

## Remediation

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

## Package advisory (CVE-2026-77582)

Affected packages:

- `github.com/tinyauthapp/tinyauth < 1.0.1-0.20260714134959-c22925c2fba9`

Patched in:

- `github.com/tinyauthapp/tinyauth 1.0.1-0.20260714134959-c22925c2fba9`

Source: https://github.com/advisories/GHSA-456h-ww26-f758