VulnerabilityPublished 19 Aug 2025Updated 20 Aug 2025

CVE-2025-51489: MoonShine · Unrestricted File Upload

Source CVE Database V5

Not known to be exploited · CVSS 4.5 Medium · fixed in 3.12.5 : update affected systems when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

4.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.12.5

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: Required
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: 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: 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: 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 19 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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

AI-suggested

Immediately upgrade MoonShine to version 3.12.5 or later once available, as this version addresses the vulnerability.
Until patching is possible, implement strict file upload validation on the server side to restrict SVG uploads or sanitize SVG content to remove embedded scripts.
Employ Content Security Policy (CSP) headers to restrict execution of inline scripts and limit the impact of any injected JavaScript.
Enforce the principle of least privilege for user accounts, minimizing the number of users with permissions to upload or update articles.
Educate users about the risks of clicking on unexpected or suspicious links, especially those pointing to SVG files.
Monitor logs for unusual upload activity or access patterns to detect potential exploitation attempts.
Consider disabling SVG uploads entirely if not required for business operations.
Conduct regular security assessments and code reviews focusing on file upload functionality to prevent similar vulnerabilities.

Description

A Stored Cross-Site Scripting (XSS) vulnerability exists in MoonShine version < 3.12.5, allowing remote attackers to upload a malicious SVG file when creating/updating an Article and correctly execute arbitrary JavaScript when the file link is opened.

Impact

For European organizations using MoonShine CMS, this vulnerability poses a moderate risk. Attackers with authenticated access—potentially internal users or compromised accounts—can upload malicious SVG files that execute arbitrary JavaScript in the browsers of other users who view the affected articles. This can lead to theft of sensitive information such as authentication tokens, personal data, or internal communications, violating GDPR and other data protection regulations. Although the vulnerability does not directly affect system integrity or availability, the confidentiality breach can have serious compliance and reputational consequences. Organizations with collaborative content management workflows or public-facing content managed via MoonShine are particularly at risk, as attackers may leverage social engineering to induce users to open malicious links. The requirement for authentication and user interaction limits the attack surface but does not eliminate the threat, especially in environments with many users or less stringent access controls. Additionally, the lack of known exploits in the wild suggests an opportunity for proactive mitigation before widespread exploitation occurs.

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

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 27 Aug 2025, 01:07 UTC

WeaknessesCWE-434

Technical details

References

Community reviews

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