{"id":"CVE-2026-82426","title":"Description\n\nNimbus accepted the `uploadedJarLocation` argument of `submitTopology` / `submitTopologyWithOpts` as a\nserver-side path and opened it directly, without checking that it referred to a file the caller had\nactually uploaded","summary":"Description\n\nNimbus accepted the `uploadedJarLocation` argument of `submitTopology` / `submitTopologyWithOpts` as a\nserver-side path and opened it directly, without checking that it referred to a file the caller had\nactually uploaded. Th…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-22"],"vendor":"Apache Software Foundation","product":"org.apache.storm:storm-server","affected":["org.apache.storm:storm-server >= 3.0.0 < 3.1.0"],"published":"2026-09-14","updated":"2026-09-14","sourceUpdated":"2026-09-14T20:58:48.430","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-82426","references":[{"url":"https://lists.apache.org/thread/cq3xzxvvhtb6brbp9nl9p8kobnvtmnwc","label":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/13/6","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-14T19:53:24.403566Z"},"ingestedAt":"2026-09-14T15:23:07.424Z","epss":0.00509,"epssPercentile":0.42483,"slug":"CVE-2026-82426","body":"## Overview\n\nDescription\n\nNimbus accepted the `uploadedJarLocation` argument of `submitTopology` / `submitTopologyWithOpts` as a\nserver-side path and opened it directly, without checking that it referred to a file the caller had\nactually uploaded. The intended flow is that a client first calls `beginFileUpload`, which returns a path\ninside the Nimbus inbox, and uploads the jar in chunks to that location; nothing bound submission to that\nflow, and the `uploaders` map populated by `beginFileUpload` was never consulted at submit time.\n\nAn authenticated user with topology submission rights could therefore submit any path readable by the\nNimbus daemon user as their topology jar. Nimbus copied the file into the topology's jar blob, and the\nblob ACL grants the submitting subject read access, so the contents could then be retrieved with the\nordinary blob download RPCs. Candidate targets include the Nimbus Kerberos keytab, Thrift and UI TLS\nprivate keys, and `storm.yaml` with the ZooKeeper authentication payload. Possession of the Nimbus keytab\nturns an ordinary tenant into a cluster administrator.\n\nIn a deployment configured as the documentation recommends, submission is available to every\nauthenticated principal when `nimbus.users` is unset, so no elevated privilege is required.\n\nMitigation\n\nUpgrade to 3.1.0, where the submitted location is canonicalised and must resolve inside the Nimbus inbox.\n\nUsers who cannot upgrade immediately should restrict topology submission to trusted principals via\n`nimbus.users` or `nimbus.groups`, and should treat any file readable by the Nimbus daemon user as\npotentially exposed to submitters: rotate the Nimbus keytab and any TLS private keys or ZooKeeper\ncredentials reachable from that account. Local mode is unaffected.\n\n\nCredit\n\nIndependently reported to the Apache Storm PMC by n0mi1k, with a proof of concept.\n\nAlso found by the ASF using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":203304,"id":"CVE-2026-82426","ts":1789416907196,"field":"cvss","old":null,"new":"6.5"},{"seq":203303,"id":"CVE-2026-82426","ts":1789416907196,"field":"severity","old":"none","new":"medium"}]}