What is CVE-2026-42359?

CVE-2026-42359 is a high-severity vulnerability in Apache Airflow, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-06-01.

How severe is CVE-2026-42359?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in Apache Airflow

CVE-2026-42359

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.g. `return_value`) that the matching P…

Vulnerability class: Insecure Deserialization

EPSS: 0.001 (19.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Apache Airflow
Apache Software Foundation Airflow — versions 3.2.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

security@apache.org (Patch, patch, Issue Tracking)
security@apache.org (vendor-advisory, Mailing List, Vendor Advisory)
security@apache.org (related, Third Party Advisory)

Frequently asked questions

What is CVE-2026-42359?: CVE-2026-42359 is a high-severity vulnerability in Apache Airflow, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-06-01.
How severe is CVE-2026-42359?: High severity. CVSS v3 base score is 8.8 out of 10.