CVE-2026-45426: Apache Airflow: Log server JWT authorization bypass via Python lstrip() character stripping allows cross-Dag log access

[Rahul Vats <rahulvats () apache org>]

Severity: low 

Affected versions:

- Apache Airflow (apache-airflow) 3.0.0 before 3.2.2

Description:

Exploitation requires the attacker to already be an authenticated Airflow worker holding a valid Log-server JWT issued 
for at least one Dag. Apache Airflow's Log server authorized JWT tokens against Dag IDs by applying Python's 
`str.lstrip()` to the requested path segment when verifying the JWT's `sub` claim. `str.lstrip()` strips any of a *set* 
of characters from the left (not a prefix), so a JWT issued for a Dag named e.g. `dag_a` would authorize log access to 
any other Dag whose name began with any subset of the characters `{d, a, g, _}` (e.g. `dag_attacker`, `aaaa_target`, 
`_dag_secret`). Such an authenticated worker could enumerate and read worker logs of other Dags whose names happened to 
share that character-class prefix, leaking task output and error traces beyond the documented per-Dag isolation 
boundary. Affects deployments relying on per-Dag log-access scoping (multi-team, shared-executor, shared-worker 
topologies). Users are advised to upgrade to `apache-airflow` 3.2.2 or later.

Credit:

Michael Lip (theluckystrike) (finder)
Jarek Potiuk (@potiuk) (remediation developer)

References:

https://github.com/apache/airflow/pull/66749
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-45426