dalfox: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-45090 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in dalfox from Hahwul, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected dalfox versions: < 2.13.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.27% 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 dalfox 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.
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
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
Official description
Dalfox is a powerful open-source XSS scanner and utility focused on automation. Prior to 2.13.0, ParameterAnalysis in pkg/scanning/parameterAnalysis.go runs two sequential worker stages that both write to the same results channel. The channel is correctly closed after the first stage completes (close(results) at line 438), but the second stage — which processes POST-body parameters (dp) — is then launched with the same already-closed channel as its output. When a scanned parameter is reflected, processParams executes results <- paramResult on the closed channel, triggering a Go runtime panic that crashes the entire dalfox process. In server mode, the crash is remotely triggerable by any unauthenticated caller who can reach the REST API, because the default configuration has no API key and the second stage activates whenever options.Data != "" (i.e., the attacker supplies the data field) and the target reflects at least one parameter. This vulnerability is fixed in 2.13.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How developers prevent this class of flaw
- In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Use thread-safe capabilities such as the data access abstraction in Spring.
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in dalfox
- 8.2 High severity
- 7.5 High severity
- 10.0 Critical severity
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 7.8 High severity
- 8.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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