CVE-2026-59242

Description

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.

Weakness classification

• security@apache.org: CWE-502

Primary references

• security@apache.org — Issue Tracking, Patch
• security@apache.org — Mailing List, Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory