{"cve":"CVE-2018-1000656","nvd":{"published":"2018-08-20T19:31:45.340","modified":"2026-06-17T01:33:02.153","status":"Modified","description":"The Pallets Project flask version Before 0.12.3 contains a CWE-20: Improper Input Validation vulnerability in flask that can result in Large amount of memory usage possibly leading to denial of service. This attack appear to be exploitable via Attacker provides JSON data in incorrect encoding. This vulnerability appears to have been fixed in 0.12.3. NOTE: this may overlap CVE-2019-1010083.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-20"],"references":["https://github.com/pallets/flask/pull/2691","https://github.com/pallets/flask/releases/tag/0.12.3","https://lists.debian.org/debian-lts-announce/2019/08/msg00025.html","https://security.netapp.com/advisory/ntap-20190221-0001/","https://usn.ubuntu.com/4378-1/"],"products":["netapp:active_iq","netapp:hyper_converged_infrastructure","netapp:ontap_select_deploy_utility","palletsprojects:flask"],"source":"nvd","synced_at":"2026-10-19T20:52:03.425131697+00:00"},"epss":{"cve":"CVE-2018-1000656","score":0.03855,"percentile":0.90159,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-562c-5r94-xh97","url":"https://osv.dev/vulnerability/GHSA-562c-5r94-xh97","summary":"Flask is vulnerable to Denial of Service via incorrect encoding of JSON data","modified":"2025-02-21T05:29:40.872529Z","packages":[{"ecosystem":"PyPI","name":"flask","purl":"pkg:pypi/flask","ranges":["<0.12.3"],"fixed":["0.12.3"]}]},{"id":"PYSEC-2018-66","url":"https://osv.dev/vulnerability/PYSEC-2018-66","summary":"","modified":"2023-11-08T03:59:39.887416Z","packages":[{"ecosystem":"PyPI","name":"flask","purl":"pkg:pypi/flask","ranges":["<0.12.3"],"fixed":["0.12.3"]}]}],"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."]}