Vulnerability · Published May 27, 2026 · Assigned by GitHub_M

CVE-2026-45090Dalfox: Unauthenticated Remote DoS via Closed-Channel Write in `ParameterAnalysis` (server mode)

High 7.5

In plain English

A high-severity race condition in dalfox from hahwul. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.3%top 80.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/hahwul/dalfox	no fix listed	GO-2026-4999
Go	github.com/hahwul/dalfox	no fix listed	GHSA-2g4x-fq3j-cgq4
Go	github.com/hahwul/dalfox/v2	2.13.0	GO-2026-4999
Go	github.com/hahwul/dalfox/v2	2.13.0	GHSA-2g4x-fq3j-cgq4

Affected products (as reported)

Vendor	Product	Versions
hahwul	dalfox	< 2.13.0

Weakness: CWE-362, CWE-404 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/hahwul/dalfox/security/advisories/GHSA-2g4x-fq3j-cgq4 x_refsource_CONFIRM
https://github.com/hahwul/dalfox/releases/tag/v2.13.0 x_refsource_MISC