{"cve":"CVE-2026-50269","nvd":{"published":"2026-06-22T18:16:42.920","modified":"2026-10-25T23:10:00.167","status":"Analyzed","description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. 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. This vulnerability is fixed in 3.14.0.","cvss_v4":{"vector":"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","score":2.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-93","CWE-113"],"references":["https://github.com/aio-libs/aiohttp/commit/bf88077ebb14f4c29924b8e8904cba20c55c28b8","https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m6qw-4cw2-hm4m"],"products":["aiohttp:aiohttp"],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-50269","score":0.00533,"percentile":0.44737,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-m6qw-4cw2-hm4m","url":"https://osv.dev/vulnerability/GHSA-m6qw-4cw2-hm4m","summary":"aiohttp: CRLF injection in multipart headers","modified":"2026-09-10T03:51:09.078868018Z","packages":[{"ecosystem":"PyPI","name":"aiohttp","purl":"pkg:pypi/aiohttp","ranges":["<3.14.0"],"fixed":["3.14.0"]}]},{"id":"PYSEC-2026-2106","url":"https://osv.dev/vulnerability/PYSEC-2026-2106","summary":"","modified":"2026-07-13T07:15:15.667130045Z","packages":[{"ecosystem":"PyPI","name":"aiohttp","purl":"pkg:pypi/aiohttp","ranges":["<3.14.0"],"fixed":["3.14.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}