HTTP Response Splitting Affecting aiohttp package, versions [,3.14.0)
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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- published16 Jun 2026
- disclosed15 Jun 2026
- credittonghuaroot (童话)
Introduced: 15 Jun 2026
NewCVE-2026-50269 (opens in a new tab)How to fix?
Upgrade aiohttp to version 3.14.0 or higher.
Overview
Affected versions of this package are vulnerable to HTTP Response Splitting via MultipartWriter.append or Payload.headers when attacker-controlled input is included in multipart or payload headers. An attacker can inject additional headers or alter the contents of a request by supplying specially crafted input.
Note: This is only exploitable if user-controlled strings are passed into the headers parameter of MultipartWriter.append or Payload.headers.