VulnerabilityPublished 31 Mar 2026

CVE-2026-34442: freescout · Improper Input Validation

Affects freescoutSource CVE Database V5

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Not known to be exploited · CVSS 5.4 Medium : upgrade to 1.8.211 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.8.211

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade freescout and freescout-help-desk/freescout to 1.8.211.

Affected software

Product	Affected	Fixed in
freescout-help-deskfreescout	Affected <1.8.211	Fixed in 1.8.211
GitHubfreescout-help-desk/freescout`pkg:github/freescout-help-desk/freescout`Other threats	Affected <1.8.211	Fixed in 1.8.211

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade FreeScout to version 1.8.211 or later, where this vulnerability has been patched. There are no indications of alternative mitigations or temporary fixes. Users should apply the official update to remediate this issue.

Description

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.211, host header manipulation in FreeScout version (http://localhost:8080/system/status) allows an attacker to inject an arbitrary domain into generated absolute URLs. This leads to External Resource Loading and Open Redirect behavior. When the application constructs links and assets using the unvalidated Host header, user requests can be redirected to attacker-controlled domains and external resources may be loaded from malicious servers. This issue has been patched in version 1.8.211.

Impact

An attacker can exploit this vulnerability to cause users to be redirected to attacker-controlled domains and to load external resources from malicious servers. This can facilitate phishing, session hijacking, or delivery of malicious content. The confidentiality and integrity impact is low, with no availability impact reported.

Summary

CVE-2026-34442 is an improper input validation vulnerability (CWE-20) in FreeScout, a PHP Laravel-based help desk application. Before version 1.8.211, FreeScout's system status endpoint (http://localhost:8080/system/status) does not properly validate the Host header, allowing attackers to manipulate it to inject arbitrary domains into absolute URLs generated by the application. This leads to external resource loading from potentially malicious servers and open redirect issues (CWE-601, CWE-829). The vulnerability has a CVSS 3.1 base score of 5.4 (medium severity) and has been addressed in FreeScout version 1.8.211.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-601URL Redirection to Untrusted Site (Open Redirect) (opens in a new tab)
Base weaknessLikelihood of exploit: LowOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
Use an intermediate disclaimer page that provides the user with a clear warning that they are leaving the current site. Implement a long timeout before the redirect occurs, or force the user to click on the link. Be careful to avoid XSS problems (CWE-79) when generating the disclaimer page.
Architecture and Design · Enforcement by Conversion
When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.5 (opens in a new tab)
Attack patterns
Cross-Site Flashing (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-829Inclusion of Functionality from Untrusted Control Sphere (opens in a new tab)
Base weaknessOWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Enforcement by Conversion
When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Vulnerable Dependency Management (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
Infrastructure as Code (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.6 (opens in a new tab)
V14.2.3 (opens in a new tab)
V14.2.4 (opens in a new tab)
Attack patterns
Serialized Data External Linking (opens in a new tab)
DTD Injection (opens in a new tab)
Local Code Inclusion (opens in a new tab)
PHP Local File Inclusion (opens in a new tab)
Remote Code Inclusion (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Apr 2026, 04:13 UTC

WeaknessesCWE-20, CWE-601, CWE-829

Technical details

References

Community reviews

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