VulnerabilityPublished 27 Feb 2026Updated 3 Mar 2026

CVE-2026-28270: kiteworks security-advisories · Unrestricted File Upload

Affects kiteworks security-advisoriesSource CVE Database V5

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Not known to be exploited · CVSS 4.9 Medium : upgrade to 9.2.0 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

4.9Medium

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

EPSS: 1.8% chance of exploitation in 30 days – higher than 78% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9.2.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
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: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 27 Feb 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 29 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 security-advisories and kiteworks/security-advisories to 9.2.0.

Affected software

Product	Affected	Fixed in
kiteworkssecurity-advisories	Affected <9.2.0	Fixed in 9.2.0
GitHubkiteworks/security-advisories`pkg:github/kiteworks/security-advisories`Other threats	Affected <9.2.0	Fixed in 9.2.0

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

AI-suggested

Organizations should upgrade Kiteworks installations to version 9.2.0 or later, where the vulnerability is patched with enhanced file upload validation. Until upgrades can be performed, restrict administrative access strictly to trusted personnel and implement strong access controls and monitoring to detect unauthorized file uploads. Employ file integrity monitoring to identify unexpected or suspicious files on the system. Conduct regular audits of uploaded content and system configurations to ensure compliance with security policies. Additionally, consider network segmentation to limit exposure of the Kiteworks management interfaces and enable logging and alerting on administrative actions. Educate administrators on the risks of arbitrary file uploads and enforce the principle of least privilege to minimize potential insider threats. Finally, maintain up-to-date backups to recover from any integrity compromises.

Description

Kiteworks is a private data network (PDN). Prior to version 9.2.0, a vulnerability in Kiteworks configuration allows uploading of arbitrary files without proper validation. Malicious administrators could exploit this to upload unauthorized file types to the system. Version 9.2.0 contains a patch for the issue.

Impact

The primary impact of CVE-2026-28270 is on the integrity of the affected Kiteworks systems. By allowing malicious administrators to upload arbitrary files, attackers can introduce unauthorized or malicious content that may disrupt normal operations, enable privilege escalation, or facilitate further attacks such as code execution or data tampering. While confidentiality and availability are not directly compromised, the integrity breach can have cascading effects, including loss of data trustworthiness and potential exposure if malicious files are leveraged in subsequent exploits. Organizations relying on Kiteworks for secure data exchange, especially in regulated industries like finance, healthcare, or government, may face compliance risks and operational disruptions. The requirement for administrative privileges limits the scope of exploitation but does not eliminate risk, as insider threats or compromised admin accounts could exploit this vulnerability. The absence of known exploits reduces immediate risk but does not preclude future attacks.

CWE-434Unrestricted Upload of File with Dangerous Type (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #12OWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
Architecture and Design
Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
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
Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Web Service Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
File Upload (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V12.5.2 (opens in a new tab)
V13.1.5 (opens in a new tab)
V12.2.1 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/kiteworks/security-advisories/security/advisories/GHSA-v8x9-vwg6-cj45 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Mar 2026, 21:19 UTC

WeaknessesCWE-434

Technical details

References

Community reviews

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