dbcve.org
AirflowApplication · Apache

CVE-2026-33264

CRITICAL · 9.8 CVSS v3.1 Published 2026-07-07
Fix available
A fix is available. Upgrade to 3.3.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A bug in `BaseSerialization.deserialize()` allowed unrestricted `import_string()` of attacker-controlled class paths when the Scheduler / API Server loaded a serialized DAG: a DAG author could embed a malicious trigger into a DAG to gain remote code execution on the API Server / Scheduler process, crossing the Airflow security boundary that DAG-author code must never execute in those processes. Users are advised to upgrade to `apache-airflow` 3.3.0 or later. As a defense-in-depth mitigation, deployments where DAG-author trust is limited can restrict the `[core] allowed_deserialization_classes` config to a narrow allowlist.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A deserialization vulnerability in Apache Airflow's `BaseSerialization.deserialize()` method allows DAG authors to embed malicious trigger code containing attacker-controlled class paths. When the Scheduler or API Server loads a serialized DAG, the unrestricted `import_string()` call executes the malicious class, achieving RCE on the server processes and crossing the security boundary that isolates DAG-author code from Airflow infrastructure.

MitigationUpgrade to apache-airflow 3.3.0 or later to patch the vulnerability. Additionally, restrict the `[core] allowed_deserialization_classes` configuration to a narrow allowlist as a defense-in-depth measure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
AirflowApplication
Affected:< 3.3.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Airflow version
    Run 'airflow version' or inspect the installed package version with 'pip show apache-airflow'
    Affected if The version is lower than 3.3.0
  2. Verify Scheduler or API Server is in use
    Check for running 'airflow scheduler' or 'airflow webserver' processes, or review your deployment architecture for these components
    Affected if Scheduler or API Server processes are running and loading serialized DAGs
  3. Inspect DAG storage for serialized DAGs
    Review your DAG repository for DAGs using custom triggers or the triggerer functionality, or check if serialized_dag_path is configured in airflow.cfg
    Affected if Custom triggers or serialized DAG loading is in use
  4. Check allowed_deserialization_classes config
    Look for the [core] allowed_deserialization_classes setting in airflow.cfg or environment variables
    Affected if The config is not set to a restrictive allowlist (or is absent in versions below 3.3.0)

You are affected if running Apache Airflow versions below 3.3.0 with the Scheduler or API Server loading serialized DAGs that could contain attacker-controlled trigger class paths.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.3.0 or later
Fixed in 3.3.0
Vendor patch github.com →
Interim mitigation

Upgrade to apache-airflow 3.3.0 or later to patch the vulnerability. Additionally, restrict the `[core] allowed_deserialization_classes` configuration to a narrow allowlist as a defense-in-depth measure.

Recommended fix High confidence

apache-airflow 3.3.0

  1. Upgrade apache-airflow to version 3.3.0 or later using your package manager (e.g., pip install apache-airflow==3.3.0)
  2. After upgrading, restart the Airflow Scheduler and API Server services to load the fixed code
  3. As a defense-in-depth measure, configure the [core] allowed_deserialization_classes setting in airflow.cfg to restrict deserialization to a narrow allowlist of expected classes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Airflow Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,896.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-33264 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33264 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data