1Panel: Improper Neutralization of Input During Web Page Generation
CVE-2026-23525 is a high-severity improper neutralization of input during web page generation vulnerability in 1Panel from 1Panel-dev, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, but only if a user takes part, for example by opening a link or file. Affected 1Panel versions: < 1.10.34; >= 2.0.0, < 2.0.17. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of 1Panel you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| 1Panel-dev | 1Panel | < 1.10.34; >= 2.0.0, < 2.0.17 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.4 | Medium | CNA (github.com) |
| CVSS 3.1 | 8.4 | High | NVD |
Official description
1Panel is an open-source, web-based control panel for Linux server management. A stored Cross-Site Scripting (XSS) vulnerability exists in the 1Panel App Store when viewing application details. Malicious scripts can execute in the context of the user’s browser, potentially compromising session data or sensitive system interfaces. All versions of 1Panel up to and including v1.10.33-lts and v2.0.16 are affected. An attacker could publish a malicious application that, when loaded by users (locally or remotely), can execute arbitrary scripts. This may result in theft of user cookies, unauthorized access to system functions, or other actions that compromise the confidentiality, integrity, and availability of the system. The vulnerability is caused by insufficient sanitization of content rendered by the MdEditor component with the `previewOnly` attribute enabled. Specifically, the App Store renders application README content without proper XSS protection, allowing script execution during content rendering; and similar issues exist in system upgrade-related components, which can be fixed by implementing proper XSS sanitization in the MdEditor component. These vulnerabilities can be mitigated by applying proper XSS protection and sanitization when rendering content in the MdEditor component. Safe versions with a patch incorporated are v1.10.34-lts and v2.0.17.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Input During Web Page Generation
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.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
- 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 data to the application. Remember that such inputs may be obtained indirectly through API calls.
- 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 entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in 1Panel
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Neutralization of Input During Web Page Generation vulnerabilities
- 7.2 High severity
- 8.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
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