qui: Permissive Cross-domain Security Policy with Untrusted Domains
CVE-2026-30924 is a critical-severity permissive cross-domain security policy with untrusted domains vulnerability in qui from Autobrr, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected qui versions: <= 1.14.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of qui 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.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- 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
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
- NoneNo account or login is needed.
- 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:N/UI:R/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.0 | Critical | CNA (github.com) |
| CVSS 3.1 | 9.6 | Critical | NVD |
Official description
qui is a web interface for managing qBittorrent instances. Versions 1.14.1 and below use a permissive CORS policy that reflects arbitrary origins while also returning Access-Control-Allow-Credentials: true, effectively allowing any external webpage to make authenticated requests on behalf of a logged-in user. An attacker can exploit this by tricking a victim into loading a malicious webpage, which silently interacts with the application using the victim's session and potentially exfiltrating sensitive data such as API keys and account credentials, or even achieving full system compromise through the built-in External Programs manager. Exploitation requires that the victim access the application via a non-localhost hostname and load an attacker-controlled webpage, making highly targeted social-engineering attacks the most likely real-world scenario. This issue was not fixed at the time of publication.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Permissive Cross-domain Security Policy with Untrusted Domains
The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate.
How developers prevent this class of flaw
- Define a restrictive Content Security Policy or cross-domain policy file.
- Avoid using wildcards in the CSP / cross-domain policy file. Any domain matching the wildcard expression will be implicitly trusted, and can perform two-way interaction with the target server.
- For Flash, modify crossdomain.xml to use meta-policy options such as 'master-only' or 'none' to reduce the possibility of an attacker planting extraneous cross-domain policy files on a server.
More Permissive Cross-domain Security Policy with Untrusted Domains vulnerabilities (CWE-942)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Permissive Cross-domain Security Policy with Untrusted Domains vulnerabilities
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 8.1 High severity
- 8.1 High severity
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