Vulnerability · medium
Apache Airflow reserved serialization keys crash scheduler or rebuild objects (CVE-2026-111395)
Tier C · Keep an eye on it – Check if you’re affected
Who’s exposed: Airflow 3.2.x–3.3.x deployments using deadline alerts
Tier C because: Hits tech teams
Reach
Attack
Damage
Fix
Popular tool
What to do
- Upgrade Apache Airflow to 3.4.0 or later.
The Brief
- Apache Airflow 3.2.0 before 3.4.0 did not reject reserved serialization keys inside a Dag run's conf.
- A user allowed to trigger a Dag that uses a deadline alert can crash the scheduler or have crafted objects rebuilt in the Triggerer via deadline callbacks.
- The advisory is tracked as CVE-2026-111395 and rated moderate.
Why it matters
Teams running Airflow 3.2 or 3.3 with deadline alerts can have their scheduler crashed by a user who can trigger Dags, so upgrading to 3.4.0 or later closes the exposure.
The checklist behind the tier
Checklist · 2 of 10 yes
| Yes | Hits tech teams | Apache Airflow is a workflow orchestration tool that data and ops teams build and run. |
| No | Core infrastructure | Airflow is a single widely used orchestration framework, not software nearly every team runs. |
| Yes | Popular tool | Apache Airflow is a widely used, mainstream data orchestration platform. |
| No | Exploited in the wild | Open Source Security (2026-11-09) describes a disclosed flaw; it reports no observed attacks. |
| No | Public exploit | Open Source Security advisory describes the issue; it does not say exploit code or a PoC is published. |
| No | Remote, no login | Open Source Security: exploitation requires a user allowed to trigger a Dag, so credentials are needed. |
| No | Full takeover | Open Source Security: impact is scheduler crash or object rebuilding in Triggerer; no code execution or admin takeover stated. |
| No | Secrets exposed | Open Source Security reports no stolen or exposed credentials, configs, or data. |
| No | Supply chain | Open Source Security describes a input validation flaw in Airflow, not compromised packages or build pipelines. |
| No | No fix yet | Open Source Security: affected versions are 3.2.0 before 3.4.0, implying a fix is available in 3.4.0. |
The official record
From CVE.org, CISA’s Known Exploited Vulnerabilities catalog, FIRST EPSS and the GitHub Advisory Database. Where these answer a checklist fact, they win over the reporting.
- Exploited
- Not in CISA’s exploited catalog
Timeline
Vulnerability advisory posted to the oss-security list by Rahul Vats
Open Source Security
CVE-2026-111395: Apache Airflow: Reserved serialization keys in Dag run conf crash the scheduler or are rebuilt as objects in the Triggerer via deadline callbacks
Source
CVE-2026-111395: Apache Airflow: Reserved serialization keys in Dag run conf crash the scheduler or are rebuilt as objects in the Triggerer via deadline callbacks ↗ Open Source Security · 3h ago
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