{"cve":"CVE-2026-34516","nvd":{"published":"2026-04-01T21:16:59.723","modified":"2026-10-26T00:10:00.150","status":"Analyzed","description":"AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, a response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability. This issue has been patched in version 3.13.4.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U","score":6.6},"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-770"],"references":["https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f","https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4","https://github.com/aio-libs/aiohttp/security/advisories/GHSA-m5qp-6w8w-w647"],"products":["aiohttp:aiohttp"],"source":"nvd","synced_at":"2026-10-26T00:31:35.753532240+00:00"},"epss":{"cve":"CVE-2026-34516","score":0.0044,"percentile":0.3798,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-m5qp-6w8w-w647","url":"https://osv.dev/vulnerability/GHSA-m5qp-6w8w-w647","summary":"AIOHTTP has a Multipart Header Size Bypass","modified":"2026-09-10T03:51:02.372876858Z","packages":[{"ecosystem":"PyPI","name":"aiohttp","purl":"pkg:pypi/aiohttp","ranges":["<3.13.4"],"fixed":["3.13.4"]}]},{"id":"PYSEC-2026-2098","url":"https://osv.dev/vulnerability/PYSEC-2026-2098","summary":"","modified":"2026-07-13T07:15:20.606847597Z","packages":[{"ecosystem":"PyPI","name":"aiohttp","purl":"pkg:pypi/aiohttp","ranges":["<3.13.4"],"fixed":["3.13.4"]}]}],"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."]}