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Medium

Apache Airflow's XCom `GET /api/v2/{...}/xcomEntries/{key}?deserialize=true` endpoint passed a string-literal payload through `BaseXCom.deserialize_value` without the `_check_forbidden_xcom_keys` guar

  • Disclosed: 12.08.2026
  • Updated: 15.10.2026 18:17

Apache Airflow's XCom GET /api/v2/{...}/xcomEntries/{key}?deserialize=true endpoint passed a string-literal payload through BaseXCom.deserialize_value without the _check_forbidden_xcom_keys guard, allowing an authenticated API user with XCom write-and-read access to instantiate arbitrary airflow.* classes on the API server (CWE-502). An authenticated user who can write an XCom value and then read it back with deserialize=true triggers the unsafe instantiation. Users are advised to upgrade to apache-airflow 3.3.1 or later, which rejects reserved XCom serialization keys submitted as JSON string literals.

Affected software

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PlatformPackageVulnerable versionsFixed in
Python (PyPI) apache-airflow < 3.3.1 3.3.1

References

CVSS score 5.4/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness (CWE)
CWE-502
Platform
Python (PyPI)
Package
apache-airflow
Disclosed
12.08.2026
Updated
15.10.2026 18:17

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-3992 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-fcmm-42r9-mmmm - CC BY 4.0

Vulnerability history: apache-airflow

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (158) in the archive
Total entries
158
First → latest
08.2018 09.2026
Without a fix
4
Exploited in attacks
2

Severity breakdown

  • Critical 16
  • High 49
  • Medium 86
  • Low 7

Disclosures per year

Severity:
  1. Apache Airflow: the Core API logout endpoint revokes only a session token presented as the _token cookie. When a client logs out presenting its credential as an Authorization bearer header instead, th
    Critical · 9.1 CVE-2026-86473 >= 3.0.0, < 3.3.2 3.3.2
  2. 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()`
    High · 7.5 CVE-2026-68968 < 3.3.1 3.3.1
  3. Apache Airflow's Task SDK rebuilt a `Callback` object from serialized data by re-running its constructor, which imports the module named by the stored callback path. Because `SyncCallback` is itself a
    High · 8.8 CVE-2026-67587 >= 3.3.0, < 3.3.1 3.3.1
  4. Apache Airflow 3.3.0 moved human-in-the-loop tasks from the triggerer to a new `awaiting_input` task state swept by the scheduler. That sweep deserializes the task instance's `next_kwargs` without an
    High · 7.3 CVE-2026-67260 >= 3.3.0, < 3.3.1 3.3.1
  5. Apache Airflow's XCom `GET /api/v2/{...}/xcomEntries/{key}?deserialize=true` endpoint passed a string-literal payload through `BaseXCom.deserialize_value` without the `_check_forbidden_xcom_keys` guar this entry
    Medium · 5.4 CVE-2026-59242 < 3.3.1 3.3.1
  6. Apache Airflow's serialization layer reconstructed exception nodes by calling `import_string()` on a class name taken from the serialized blob and instantiating it with arguments from the same blob, w
    High · 8.8 CVE-2026-58076 >= 3.3.0, < 3.3.1 3.3.1
  7. 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
    Critical · 9.8 CVE-2026-33264 < 3.3.0 3.3.0
  8. A bug in Apache Airflow's XCom PATCH endpoint `PATCH /api/v2/xcomEntries/{key}` allowed an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e
    High · 8.8 CVE-2026-42359 >= 3.2.0, < 3.2.2 3.2.2
  9. A bug in Apache Airflow's bulk Task Instances API (`PATCH/DELETE /api/v2/dags/{dag_id}/dagRuns/{dag_run_id}/taskInstances`) evaluated authorization against the `dag_id` resolved from the URL path whil
    High · 7.5 CVE-2026-41084 >= 3.2.0, < 3.2.2 3.2.2
  10. Apache Airflow's official documentation at `core-concepts/dag-run.html` ("Passing Parameters when triggering Dags") showed a verbatim `BashOperator(bash_command="echo value: {{ dag_run.conf['conf1'] }
    Critical · 9.1 CVE-2026-42252 >= 3.0.0, < 3.2.2 3.2.2
  11. Apache Airflow: Authenticated users can bypass the `is_safe_url` check
    High · 7.2 CVE-2026-40961 < 3.2.2 3.2.2
  12. Apache Airflow Vulnerable to Deserialization of Untrusted Data
    High · 7.3 CVE-2026-45360 >= 3.2.0, < 3.2.2 3.2.2
  13. Apache Airflow allows code execution through crafted XCom payloads
    High · 7.2 CVE-2026-25917 < 3.2.0 3.2.0
  14. Apache Airflow: JWT token appearing in logs
    High · 7.5 CVE-2026-31987 >= 3.0.0, < 3.2.0 3.2.0
  15. Apache Airflow: RCE by race condition in example_xcom dag
    High · 8.1 CVE-2025-54550 < 3.2.0 3.2.0
  16. Dag Authors, who normally should not be able to execute code in the webserver context could craft XCom payload causing the webserver to execute arbitrary code. Since Dag Authors are already highly tru
    High · 8.8 CVE-2026-33858 >= 3.1.8, < 3.2.0 3.2.0
  17. Apache Airflow: JWT token still valid after logout
    Critical · 9.1 CVE-2025-57735 >= 3.0.0, < 3.2.0 3.2.0
  18. Apache Airflow versions 3.1.0 through 3.1.7 missing authorization vulnerability in the Execution API's Human-in-the-Loop (HITL) endpoints that allows any authenticated task instance to read, approve,
    High · 8.1 CVE-2026-30911 >= 3.1.0, < 3.1.8 3.1.8
  19. Apache Airflow versions 3.1.0 through 3.1.7 session token (_token) in cookies is set to path=/ regardless of the configured [webserver] base_url or [api] base_url.
    High · 7.5 CVE-2026-28779 >= 3.0.0, < 3.1.8 3.1.8
  20. Apache Airflow vulnerable to Code Injection in the web-server context via LogTemplate table
    High · 8.4 CVE-2024-56373 < 2.11.1 2.11.1
Show more (20) Showing 20 of 66

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