{"cve":"CVE-2026-42812","nvd":{"published":"2026-05-04T17:16:26.887","modified":"2026-10-26T19:10:00.163","status":"Analyzed","description":"In Apache Iceberg, the table's metadata files are control files: they tell readers\nwhich data files belong to the table and which table version to read.\n\n\n\n`write.metadata.path` is an optional table property that tells Polaris\nwhere to\nwrite those metadata files. \nFor a table already registered in a\nPolaris-managed\ncatalog, changing only that property through an `ALTER TABLE`-style settings\nchange (not a row-level `INSERT`, `SELECT`, `UPDATE`, or `DELETE`) bypasses\nthe commit-time branch that is supposed to revalidate storage locations.\n\nThe full persisted / credential-vending variant requires the affected\ncatalog\nto have `polaris.config.allow.unstructured.table.location=true`, with\n`allowedLocations` broad enough to include the attacker-chosen target.\n\n\n`allowedLocations` is the admin-configured allowlist of storage paths that\nthe\ncatalog is allowed to use. Public project materials suggest that this flag\nis a\nreal supported compatibility / layout mode, not just a contrived lab-only\nprerequisite.\n\n\nIn that configuration, a user who can change table settings can cause Apache Polaris\nitself to write new table metadata to an attacker-chosen reachable storage\nlocation before the intended location-validation branch runs.\n\nIf the later concrete-path validation also accepts that location, Polaris\npersists the resulting metadata path into stored table state. Later\ntable-load\nand credential APIs can then return temporary cloud-storage credentials for\nthe\nsame location without revalidating it. In plain terms, Polaris can later\nhand\nout temporary storage access for the same attacker-chosen area.\n\nThat attacker-chosen area does not need to be limited to the poisoned\ntable's\nown files. If it is a broader storage prefix, another table's prefix, or,\ndepending on configuration or provider behavior, even a bucket/container\nroot,\nthe resulting disclosure or corruption scope can extend to any data and\nmetadata Polaris can reach there.\n\n\n\nThe practical consequences are therefore similar to the staged-create\ncredential-vending issue already discussed: data and metadata reachable in\nthat\nstorage scope can be exposed and, if write-capable credentials are later\nissued, modified, corrupted, or removed. Even before that later credential\nstep, Polaris itself performs the metadata write to the unchecked location.\n\nSo the core issue is not only later credential vending. \n\nThe primary defect\nis\nthat Polaris skips its intended location checks before performing a\nsecurity-\nsensitive metadata write when only `write.metadata.path` changes.\n\n\n\nWhen `polaris.config.allow.unstructured.table.location=false`, current code\nreview suggests the later `updateTableLike(...)` validation usually rejects\nout-of-tree metadata locations before the unsafe path is persisted. That may\nreduce the persisted / credential-vending variant, but it does not prevent\nthe\nunderlying defect: Polaris still skips the intended pre-write location check\nwhen only `write.metadata.path` changes.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","score":9.4},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":9.9},"cwes":["CWE-20","CWE-284","CWE-732","CWE-863"],"references":["https://lists.apache.org/thread/wxd2wj3p0smvrk84msv317wg5tp3jtw9","http://www.openwall.com/lists/oss-security/2026/05/02/13"],"products":["apache:polaris"],"source":"nvd","synced_at":"2026-10-26T19:31:02.781428341+00:00"},"epss":{"cve":"CVE-2026-42812","score":0.00365,"percentile":0.30087,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-w76p-3cgp-qfcm","url":"https://osv.dev/vulnerability/GHSA-w76p-3cgp-qfcm","summary":"Apache Polaris has an Improper Input Validation issue","modified":"2026-08-31T23:00:09.804903645Z","packages":[{"ecosystem":"Maven","name":"org.apache.polaris:polaris-runtime-service","purl":"pkg:maven/org.apache.polaris/polaris-runtime-service","ranges":[">=0.9.0 <1.4.1"],"fixed":["1.4.1"]}]}],"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."]}