CRLF Injection Affecting httpx2 package, versions [,2.11.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published1 Oct 2026
- disclosed8 Sept 2026
- creditmaxisbey
Introduced: 8 Sep 2026
NewCVE-2026-84379 (opens in a new tab)How to fix?
Upgrade httpx2 to version 2.11.0 or higher.
Overview
httpx2 is a The next generation HTTP client.
Affected versions of this package are vulnerable to CRLF Injection in the FileField.render_headers() method, which writes the per file content_type value and any custom header names and values into the multipart part header block without rejecting CR or LF characters. An attacker can inject additional part headers into the request or terminate the part header block early, altering how the receiving server interprets the part and bypassing checks it makes on part headers, by placing a CRLF sequence in upload metadata that the application passes through to the files= tuple. This requires the application to take the per file content_type or headers arguments from attacker influenced data rather than setting them itself, and the effect lands on whatever the upload is sent to, so the consequence depends on that server's own multipart parsing and validation.