aio-libs/aiohttp · Security
aiohttp: CRLF injection in multipart headers
- GHSA ID
- GHSA-m6qw-4cw2-hm4m
- CVE ID
- CVE-2026-50269
- Severity
- low
- Published
- Updated
- CVSS v4
- 2.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
Description
Summary
Attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar.
Impact
In the unlikely situation that an application is passing user-controlled strings into MultipartWriter.append(headers=...) or Payload.headers, then an attacker may be able to modify the request to inject headers or change the contents of the request.
Workaround
Sanitise such user input.
Patch: https://github.com/aio-libs/aiohttp/commit/bf88077ebb14f4c29924b8e8904cba20c55c28b8
CWEs
- CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')
- CWE-113 · Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')