VulnerabilityPublished 13 May 2026

CVE-2026-44423: shellhub · Insecure Direct Object Reference

Affects shellhubSource CVE Database V5

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Not known to be exploited · CVSS 6.5 Medium : upgrade to 0.24.2 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.24.2

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within 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 13 May 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 shellhub and shellhub-io/shellhub to 0.24.2.

Affected software

Product	Affected	Fixed in
shellhub-ioshellhub	Affected <0.24.2	Fixed in 0.24.2
GitHubshellhub-io/shellhub`pkg:github/shellhub-io/shellhub`Other threats	Affected <0.24.2	Fixed in 0.24.2

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

AI-suggested

Upgrade ShellHub to version 0.24.2 or later, where this authorization bypass vulnerability has been fixed. Until upgraded, restrict access to trusted users only and monitor for unauthorized access attempts. Patch status is not explicitly confirmed beyond the version fix statement; check vendor sources for current remediation guidance.

Description

ShellHub versions prior to 0.24.2 contain an authorization bypass vulnerability where authenticated users can access full session objects belonging to other tenants. This allows reading sensitive session details such as SSH usernames, device UIDs, remote IPs, terminal types, authentication flags, and timestamps without proper tenant scoping. The issue is addressed in version 0.24.2.

Impact

An authenticated user can read sensitive session information from other tenants, including SSH usernames, device unique identifiers, remote IP addresses, terminal types, authentication status, and timestamps. This exposure compromises confidentiality of session data across tenant boundaries but does not affect integrity or availability. There are no known exploits in the wild.

Summary

CVE-2026-44423 is an authorization bypass vulnerability in ShellHub, a centralized SSH gateway. Before version 0.24.2, the API endpoint GET /api/sessions/:uid returns the complete session object for any authenticated user without restricting access to the user's own tenant namespace. This flaw enables an authenticated user to access session records of other tenants, exposing sensitive session metadata. The vulnerability is identified as CWE-639 (Authorization Bypass Through User-Controlled Key) and has a CVSS 3.1 base score of 6.5, indicating medium severity. No official remediation level or patch links are provided in the data, but the description states the issue is fixed in version 0.24.2.

CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/shellhub-io/shellhub/security/advisories/GHSA-9w9c-9w8m-w89q (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 21 May 2026, 12:24 UTC

WeaknessesCWE-639

Technical details

References

Community reviews

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