{"id":"CVE-2026-82441","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-82441","generatedAt":"2026-09-20T15:57:34.411Z","title":"Separately, on acquiring leadership a Nimbus compares the dependency keys of all active topologies against the blobstore contents and surrenders leadership if any is missing.","description":"Description\n\nA submitted topology carries two lists of blobstore keys, `dependency_jars` and `dependency_artifacts`,\nwhich the client fills in after uploading the corresponding blobs. Nimbus performed no validation of their\ncontents on the submission path, yet acts on them in two places.\n\nDuring cleanup of a finished topology, Nimbus deletes the keys named in those lists, and the deletion is\nperformed as the Nimbus subject, for which the blobstore short-circuits its ACL check. A submitter who\nlisted a key belonging to another topology, such as its `-stormjar.jar`, could therefore cause\nthat blob to be deleted when their own topology was cleaned up.\n\nSeparately, on acquiring leadership a Nimbus compares the dependency keys of all active topologies against\nthe blobstore contents and surrenders leadership if any is missing. A single key that does not exist, on a\nsingle active topology, therefore causes every Nimbus to acquire leadership, surrender it and requeue\nindefinitely, leaving the cluster without a leader and unable to schedule, clean up or accept submissions.\n\nMitigation\n\nUpgrade to 3.1.0, where a submission is refused unless every entry in both lists is a dependency blob key\nand exists in the blobstore.\n\nNote that this validates new submissions only; a topology stored by an affected version with an invalid list\nis unaffected by the upgrade. An operator whose cluster is failing to retain a leader should inspect the\nNimbus log for the dependency keys reported as missing and remove or resubmit the topology naming them.\n\nUsers who cannot upgrade immediately should restrict topology submission to trusted principals.\n\nCredit\n\nThis issue was discovered by rzo1 while investigating an unrelated blobstore defect.","published":"2026-09-14T14:17:13.000Z","lastModified":"2026-09-14T20:58:48.000Z","status":"Deferred","sourceIdentifier":"security@apache.org","cvss":{"version":"3.1","score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-20","CWE-639"],"affected":[],"epss":{"score":0.0042,"percentile":0.35979,"date":"2026-09-19","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://lists.apache.org/thread/qzh245bczoxw4mfnyvrj3dj2crtzdso8","source":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/13/19","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-82441","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}