{"cve":"CVE-2021-32040","nvd":{"published":"2022-04-12T15:15:07.707","modified":"2026-06-17T03:52:43.110","status":"Modified","description":"It may be possible to have an extremely long aggregation pipeline in conjunction with a specific stage/operator and cause a stack overflow due to the size of the stack frames used by that stage. If an attacker could cause such an aggregation to occur, they could maliciously crash MongoDB in a DoS attack. This vulnerability affects MongoDB Server v4.4 versions prior to and including 4.4.28, MongoDB Server v5.0 versions prior to 5.0.4 and MongoDB Server v4.2 versions prior to 4.2.16.\n\nWorkaround: >= v4.2.16 users and all v4.4 users can add the --setParameter internalPipelineLengthLimit=50 instead of the default 1000 to mongod at startup to prevent a crash.","cvss_v4":null,"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-787","CWE-121"],"references":["https://jira.mongodb.org/browse/SERVER-58203","https://jira.mongodb.org/browse/SERVER-59299","https://jira.mongodb.org/browse/SERVER-60218","https://security.netapp.com/advisory/ntap-20220609-0005/","https://jira.mongodb.org/browse/SERVER-58203"],"products":["mongodb:mongodb"],"source":"nvd","synced_at":"2026-10-19T21:30:03.577988018+00:00"},"epss":{"cve":"CVE-2021-32040","score":0.02011,"percentile":0.80871,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}