Auth bypass in Apache Polaris

CVE-2026-42809

Apache Polaris can issue broad temporary ("vended") storage credentials during staged table creation before the effective table location has been validated or durably reserved. Those temporary credentials are meant to limit the scope of accessible table data and metadata, but this scope limitation becomes attacker- directed because the attacker can choose a reachable target location. In the confirmed variant, if the caller supplies a custom `location` during stage create and requests credential vending, Apache Polaris uses that location to construct delegated storage credentials immediately. The stage-create path itself neither runs the normal location validation nor the overlap checks before those credentials are issued. Closely related to that, the staged-create flow also accepts `write.data.path` / `write.metadata.path` in the request properties and feeds those location overrides into the same effective table location set used for credential vending. Those fields are secondary to the main custom-`location` exploit, but they are still attacker-influenced location inputs that should be validated before any credentials are issued.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (29.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42809: held from 0.006 to 0.004.

EPSS over last 30 days · oldest: 0.006 · newest: 0.004 · change: -0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42809?
CVE-2026-42809 is a critical-severity vulnerability in Apache Polaris, classified under Improper Input Validation. CVSS score: 9.9/10. Published 2026-05-04.
How severe is CVE-2026-42809?
Critical severity. CVSS v3 base score is 9.9 out of 10.