{"id":"BIT-mongodb-2026-18709","summary":"Missing Authorization in MongoDB Sharded Transaction Commit/Abort Handling Leads to Cross-Shard Data Inconsistency","details":"An issue in MongoDB Server could allow an authenticated user with direct network access to a shard to improperly commit or abort an in-progress prepared transaction, bypassing the intended transaction coordination process. This could result in cross-shard data inconsistency, cluster clock corruption, and violation of transaction atomicity guarantees.","aliases":["CVE-2026-18709"],"modified":"2026-09-17T14:45:08.858781945Z","published":"2026-09-17T11:50:15.944Z","database_specific":{"cpes":["cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*","cpe:2.3:a:mongodb:mongodb:*:*:*:*:-:-:*:*"],"severity":"Medium"},"references":[{"type":"ADVISORY","url":"https://jira.mongodb.org/browse/SERVER-130544"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18709"}],"affected":[{"package":{"name":"mongodb","ecosystem":"Bitnami","purl":"pkg:bitnami/mongodb"},"ranges":[{"type":"SEMVER","events":[{"introduced":"7.0.0"},{"fixed":"7.0.40"},{"introduced":"8.0.0"},{"fixed":"8.0.29"},{"introduced":"8.2.0"},{"fixed":"8.3.8"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/mongodb/BIT-mongodb-2026-18709.json"},"severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}],"schema_version":"1.9.0"}