HTTP Request Smuggling Affecting py3-httpx2 package, versions <2.12.0-r0
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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- published12 Sept 2026
- disclosed2 Sept 2026
Introduced: 2 Sep 2026
NewCVE-2026-84380 (opens in a new tab)How to fix?
Upgrade Wolfi py3-httpx2 to version 2.12.0-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream py3-httpx2 package and not the py3-httpx2 package as distributed by Wolfi.
See How to fix? for Wolfi relevant fixed versions and status.
HTTPX2 is a next generation HTTP client for Python. Prior to 2.11.0, Request._prepare() in src/httpx2/httpx2/_models.py can add a body-derived Content-Length header to a request that already contains a caller-supplied Transfer-Encoding header because its setdefault() processing checks each default header independently rather than treating the two framing headers as mutually exclusive. Fixed-size byte, JSON, form, and known-length multipart bodies can therefore be serialized over HTTP/1.1 with both headers, allowing request smuggling or connection desynchronization when downstream intermediaries disagree about which framing header takes precedence. This issue is fixed in version 2.11.0.