CVE-2026-53595
FreeScout vulnerable to anonymous account takeover via /user-setup empty invite_hash on MySQL
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the public endpoint POST /user-setup/{hash}/{invite_sent_at} (OpenController@userSetupSave) selects the target account solely by its invite_hash column, then overwrites that account's email and password and logs in as it. No authentication, cookie, or prior session is required. After a user activates, FreeScout sets invite_hash to the empty string. On MySQL and MariaDB, VARCHAR equality ignores trailing spaces, so a single URL-encoded space (%20) matches the stored empty string and selects the lowest-id activated user. The expiry guard decrypts invite_sent_at with the target's password hash, but Helper::decrypt returns its raw input unchanged when decryption fails. A plaintext numeric value such as 9999999999 therefore passes the time-to-live check without any secret. The result is that an anonymous attacker sets the email and password of the lowest-id activated FreeScout account (a support agent, or an administrator if one was added by invitation) and authenticates as that account. Version 1.8.224 contains a fix.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
9.4
FreeScout vulnerable to anonymous account takeover via /user-setup empty invite_hash on MySQL
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the public endpoint POST /user-setup/{hash}/{invite_sent_at} (OpenController@userSetupSave) selects the target account solely by its invite_hash column, then overwrites that account's email and password and logs in as it. No authentication, cookie, or prior session is required. After a user activates, FreeScout sets invite_hash to the empty string. On MySQL and MariaDB, VARCHAR equality ignores trailing spaces, so a single URL-encoded space (%20) matches the stored empty string and selects the lowest-id activated user. The expiry guard decrypts invite_sent_at with the target's password hash, but Helper::decrypt returns its raw input unchanged when decryption fails. A plaintext numeric value such as 9999999999 therefore passes the time-to-live check without any secret. The result is that an anonymous attacker sets the email and password of the lowest-id activated FreeScout account (a support agent, or an administrator if one was added by invitation) and authenticates as that account. Version 1.8.224 contains a fix.
- Record
CVE-2026-53595- CVSS 3.1
- 9.4 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L - Weakness
- CWE-178, CWE-287, CWE-640
- Updated
- 2026-11-02
EUVDEUVD-2026-46094
9.4
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the public endpoint POST /user-setup/{hash}/{invite_sent_at} (OpenController@userSetupSave) selects the target account solely by its invite_hash column, then overwrites that account's email and password and logs in as it. No authentication, cookie, or prior session is required. After a user activates, FreeScout sets invite_hash to the empty string. On MySQL and MariaDB, VARCHAR equality ignores trailing spaces, so a single URL-encoded space (%20) matches the stored empty string and selects the lowest-id activated user. The expiry guard decrypts invite_sent_at with the target's password hash, but Helper::decrypt returns its raw input unchanged when decryption fails. A plaintext numeric value such as 9999999999 therefore passes the time-to-live check without any secret. The result is that an anonymous attacker sets the email and password of the lowest-id activated FreeScout account (a support agent, or an administrator if one was added by invitation) and authenticates as that account. Version 1.8.224 contains a fix.
- Record
EUVD-2026-46094- CVSS 3.1
- 9.4 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L - Updated
- 2026-11-02
NVD
9.4
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the public endpoint POST /user-setup/{hash}/{invite_sent_at} (OpenController@userSetupSave) selects the target account solely by its invite_hash column, then overwrites that account's email and password and logs in as it. No authentication, cookie, or prior session is required. After a user activates, FreeScout sets invite_hash to the empty string. On MySQL and MariaDB, VARCHAR equality ignores trailing spaces, so a single URL-encoded space (%20) matches the stored empty string and selects the lowest-id activated user. The expiry guard decrypts invite_sent_at with the target's password hash, but Helper::decrypt returns its raw input unchanged when decryption fails. A plaintext numeric value such as 9999999999 therefore passes the time-to-live check without any secret. The result is that an anonymous attacker sets the email and password of the lowest-id activated FreeScout account (a support agent, or an administrator if one was added by invitation) and authenticates as that account. Version 1.8.224 contains a fix.
- Record
CVE-2026-53595- CVSS 3.1
- 9.4 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L - Weakness
- CWE-178, CWE-287, CWE-640
- Updated
- 2026-11-02
OSV
9.4
FreeScout vulnerable to anonymous account takeover via /user-setup empty invite_hash on MySQL
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the public endpoint POST /user-setup/{hash}/{invite_sent_at} (OpenController@userSetupSave) selects the target account solely by its invite_hash column, then overwrites that account's email and password and logs in as it. No authentication, cookie, or prior session is required. After a user activates, FreeScout sets invite_hash to the empty string. On MySQL and MariaDB, VARCHAR equality ignores trailing spaces, so a single URL-encoded space (%20) matches the stored empty string and selects the lowest-id activated user. The expiry guard decrypts invite_sent_at with the target's password hash, but Helper::decrypt returns its raw input unchanged when decryption fails. A plaintext numeric value such as 9999999999 therefore passes the time-to-live check without any secret. The result is that an anonymous attacker sets the email and password of the lowest-id activated FreeScout account (a support agent, or an administrator if one was added by invitation) and authenticates as that account. Version 1.8.224 contains a fix.
- Record
CVE-2026-53595- CVSS 3.1
- 9.4 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L - Weakness
- CWE-178, CWE-287, CWE-640
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | FreeScout < 1.8.224 - Invite Hash Authorization Bypass | |
| PoC in GitHub | 0xdak/CVE-2026-53595_exploit | 2026-07-21 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, Nuclei, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-53595 is a critical vulnerability (CVSS 9.4) in Freescout-help-desk Freescout, published July 20, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 1.94%, the 80th percentile. No source names a fixed version.