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CVE-2026-33264· NVD / CVE Program· CNA apache

Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()

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.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Jul 7, 2026
Updated
Jul 8, 2026
EPSS
1.6% · 76th percentile
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Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Affected systems

VendorProduct
apacheairflow

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache airflowbefore 3.3.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache Airflow

    • before 3.3.0affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPIapache-airflowbefore 3.3.03.3.0

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-13927The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security riKEV
    99Now
  • CVE-2020-11978An issue was found in Apache Airflow versions 1.10.10 and below.KEV
    95Now
  • CVE-2021-38540Apache Airflow: Variable Import endpoint missed authentication check
    63This week
  • CVE-2022-40127Apache Airflow <2.4.0 has an RCE in a bash example
    61This week
  • CVE-2022-24288Apache Airflow: RCE in example DAGs
    58Plan
  • CVE-2020-11981An issue was found in Apache Airflow versions 1.10.10 and below.
    50Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Apache Software Foundation Apache Airflow3.3.0Vendor (CNA)
PyPI:apache-airflow3.3.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-4235936 days apartApache Airflow: Authenticated RCE via XCom PATCH endpoint — XComUpdateBody missing FORBIDDEN_XCOM_KEYS validator
    35Monitor
  • CVE-2026-5807636 days apartApache Airflow: Unguarded import_string() of airflow_exc_ser / base_exc_ser exception nodes in BaseSerialization.deserialize enables DAG-author RCE on Scheduler
    35Monitor
  • CVE-2026-6758736 days apartApache Airflow: DAG-author remote code execution on the Scheduler via a Serde `Callback` deserialization gadget
    35Monitor
  • CVE-2026-3385885 days apartApache Airflow: Unsafe Deserialization via Legacy Serialization Keys (__type/__var) Bypass in XCom API
    35Monitor
  • CVE-2026-4536036 days apartApache Airflow: Arbitrary import in custom deadline-reference deserialization
    29Monitor
  • CVE-2026-6726036 days apartApache Airflow: DAG-author remote code execution on the Scheduler via awaiting_input next_kwargs deserialization
    29Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-secondary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python
payload = sock.recv(65536)job = pickle.loads(payload)

Fixed

python
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig):    raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records