CVE-2026-53595Public exploitNetwork attack vector

Unauthenticated account takeover via empty invite hash

Published Jul 20, 2026 · Updated Jul 20, 2026

Authentication bypass in FreeScout before 1.8.224 allows remote attackers to take over an activated agent account through a public setup route. OpenController@userSetupSave matches a space against an empty invite_hash on MySQL or MariaDB, while failed invite-time decryption returns attacker input and accepts a future numeric timestamp. The attack requires an activated non-installer user and overwrites the lowest-ID matching account's email and password without authentication or user interaction.

CVSS severity9.4
Critical
EPSS probability1.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in FreeScout before 1.8.224 allows remote attackers to take over an activated agent account through a public setup route. OpenController@userSetupSave matches a space against an empty invite_hash on MySQL or MariaDB, while failed invite-time decryption returns attacker input and accepts a future numeric timestamp. The attack requires an activated non-installer user and overwrites the lowest-ID matching account's email and password without authentication or user interaction.

The record

CVE
CVE-2026-53595
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
FreeScout
Product
FreeScout
Classifications
CWE-640, CWE-178, CWE-287, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.8.224

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeScout · FreeScoutversion=< 1.8.224

Published CVSS scores

9.4GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-640Weak Password Recovery Mechanism for Forgotten Password
CWE-178Improper Handling of Case Sensitivity
CWE-287Improper Authentication
T1078Valid Accounts

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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