{"id":"CVE-2026-59242","state":"PUBLISHED","title":"Apache Airflow: Arbitrary airflow.* class instantiation on the API server via the XCom deserialize endpoint","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.","publishedAt":"2026-08-12T15:35:00.763Z","updatedAt":"2026-09-16T14:55:43.129Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","source":"CISA-ADP"},"assigner":"apache","products":["Apache Software Foundation Apache Airflow"],"affected":[{"vendor":"Apache Software Foundation","product":"Apache Airflow","packageName":"apache-airflow","packageURL":"pkg:pypi/apache-airflow","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.3.1","versionType":"semver"}],"collectionURL":"https://pypi.python.org"}],"references":["https://github.com/apache/airflow/pull/69378","https://lists.apache.org/thread/dm0520yhh4mn7qknyoh45r2w6c5qg2mg","http://www.openwall.com/lists/oss-security/2026/08/12/6"],"weaknesses":["CWE-502"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59242.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59242","state":"PUBLISHED","datePublished":"2026-08-12T15:35:00.763Z","dateUpdated":"2026-09-16T14:55:43.129Z","assignerShortName":"apache","assignerOrgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateReserved":"2026-07-04T00:17:45.922Z"},"containers":{"cna":{"title":"Apache Airflow: Arbitrary airflow.* class instantiation on the API server via the XCom deserialize endpoint","descriptions":[{"lang":"en","value":"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":[{"vendor":"Apache Software Foundation","product":"Apache Airflow","packageName":"apache-airflow","packageURL":"pkg:pypi/apache-airflow","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.3.1","versionType":"semver"}],"collectionURL":"https://pypi.python.org"}],"references":[{"url":"https://github.com/apache/airflow/pull/69378","tags":["patch"]},{"url":"https://lists.apache.org/thread/dm0520yhh4mn7qknyoh45r2w6c5qg2mg","tags":["vendor-advisory"]}],"metrics":[{"other":{"content":{"text":"important"},"type":"Textual description of severity"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-502","description":"CWE-502: Deserialization of Untrusted Data","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"apache","orgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateUpdated":"2026-09-16T14:55:43.129Z"},"credits":[{"lang":"en","type":"finder","value":"localhost-detect (@localhost-detect)"},{"lang":"en","type":"remediation developer","value":"Jarek Potiuk"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"airflow-s/generate_cve_json.py"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.4,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"LOW","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-08-12T16:41:51.650384Z","id":"CVE-2026-59242","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-12T16:41:55.648Z"}},{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/08/12/6"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-08-12T17:20:18.016Z"}}]}}}