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CRITICALpublic exploit

CVE-2026-53595

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…

Published Updated Sources: cvelistV5, GitHub_M

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Exploit code

public exploit, none observed

EPSS

2%

chance of exploitation in 30 days

Affects

freescout help desk

freescout

CVSS base

9.4

CRITICAL

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

PoC

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Products (1)

freescout

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactSource
9.4CVSS 3.1CRITICAL——cvelistV5

Weakness & attack patterns

  • CWE-178
  • CWE-287
  • CWE-640

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

  • T1548Abuse Elevation Control Mechanism
  • T1040Network Sniffing
  • T1185Browser Session Hijacking

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Indexed by

poc in github

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

  • Search application, proxy, and WAF logs for requests touching /user-setup/.

References

1 on the record

Elsewhere on this site

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.