CVE-2026-68968 Apache Airflow Backfill API Auth Bypass (pre-3.3.1)
CVE-2026-68968 Published on August 12, 2026
Apache Airflow: Authorization bypass in the Backfill API through conflicting interpretations of the backfill id
Apache Airflow's Backfill API authorized a request against a Dag id supplied by the caller whenever the `backfill_id` path segment failed to parse. The authorization dependency parsed it with `int()` while the route handler parsed it as pydantic's `NonNegativeInt`, which accepts values `int()` rejects (`1.0` coerces to `1`); FastAPI resolves dependencies before endpoint validation, so the two acted on different Dags. An authenticated user holding edit permission on any single Dag could therefore read, pause and cancel backfills belonging to any other Dag, including moving another Dag's queued runs to `failed`. No non-default configuration is required and backfill ids are sequential, so finding a target is trivial. Users are advised to upgrade to apache-airflow 3.3.1 or later, which parses the backfill id with the same type the routes declare.
Vulnerability Analysis
CVE-2026-68968 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Weakness Type
Interpretation Conflict
Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state. This is generally found in proxies, firewalls, anti-virus software, and other intermediary devices that monitor, allow, deny, or modify traffic based on how the client or server is expected to behave.
Products Associated with CVE-2026-68968
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Affected Versions
Apache Software Foundation Apache Airflow:- Before 3.3.1 is affected.