VulnerabilityPublished 12 Jun 2025Updated 18 Jun 2025

CVE-2025-5301: OnlyOffice Docs (DocumentServer) · XSS or 'Cross-site Scripting'

Affects OnlyOffice Docs (DocumentServer)Source CVE Database V5

Not known to be exploited · public detection template (Nuclei) · 62% EPSS · CVSS 6.1 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

6.1Medium

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

EPSS: 62.3% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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 12 Jun 2025
Detectable: evidence found.
nuclei template: ONLYOFFICE Docs (DocumentServer) - Reflected Cross-Site Scripting
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

Affected software

Product	Affected	Fixed in
GitHubonlyoffice/DocumentServer`pkg:github/onlyoffice/DocumentServer`Other threats	Affected <=8.3.1	Fixed in–

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

AI-suggested

Immediate mitigation should include restricting access to ONLYOFFICE Docs servers to trusted internal networks or VPNs to reduce exposure to untrusted users.
Implement Web Application Firewall (WAF) rules specifically targeting suspicious POST requests to the WOPI endpoint, filtering out payloads containing script tags or suspicious characters.
Employ Content Security Policy (CSP) headers to limit the execution of inline scripts and reduce the impact of XSS attacks.
Conduct thorough input validation and output encoding on all user-supplied data, especially data processed via the WOPI protocol, to prevent script injection.
Monitor server logs for unusual POST requests or repeated access attempts to the WOPI interface.
Educate users about the risks of clicking on untrusted links or opening files from unknown sources within ONLYOFFICE.
Stay alert for official patches or updates from OnlyOffice and prioritize their deployment once available.
Consider isolating ONLYOFFICE Docs instances in segmented network zones to limit potential lateral movement in case of compromise.

Description

ONLYOFFICE Docs (DocumentServer) in versions equal and below 8.3.1 are affected by a reflected cross-site scripting (XSS) issue when opening files via the WOPI protocol. Attackers could inject malicious scripts via crafted HTTP POST requests, which are then reflected in the server's HTML response.

Impact

For European organizations, the impact of CVE-2025-5301 could be substantial, particularly for those relying on ONLYOFFICE Docs for document collaboration and editing. Successful exploitation could compromise user sessions, leading to unauthorized access to sensitive documents and internal communications. This could result in data leakage, intellectual property theft, and disruption of business processes. Additionally, attackers could leverage the XSS vulnerability to deploy further attacks such as phishing or malware delivery within the corporate network. Given the collaborative nature of ONLYOFFICE, the vulnerability could facilitate lateral movement inside an organization’s IT infrastructure. Sectors such as finance, government, healthcare, and critical infrastructure, which often handle sensitive data and rely on document collaboration tools, are at heightened risk. The vulnerability also poses reputational risks and potential regulatory compliance issues under GDPR if personal data is exposed or mishandled due to exploitation.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
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.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: 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 external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (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 12 Jun 2025, 08:23 UTC

Public exploits and detectiona Nuclei detection template

WeaknessesCWE-79

Technical details

References

Community reviews

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