CVE-2026-59242 json
Apache Airflow: Arbitrary airflow.* class instantiation on the API server via the XCom deserialize endpoint
published 2026-08-12 2 mo ago modified 2026-11-03 6 d ago also BIT-airflow-2026-59242 , EUVD-2026-57312 , GHSA-fcmm-42r9-mmmm , PYSEC-2026-3992
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 45%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi apache-airflow 3.3.1
- bitnami airflow 3.3.1
- Apache Software Foundation Apache Airflow 3.0.0, 3.3.1
- github.com/apache/airflow@78abd30 commit
- github.com/apache/airflow@d08ddc0 commit
- github.com/apache/airflow#69378 pull request
- github.com/apache/airflow/releases/tag/3.3.1 release
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| OSV | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | apache-airflow | <3.3.1 |
3.3.1 |
| bitnami | airflow | <3.3.1 |
3.3.1 |
Affected products
- Apache Software Foundation Apache Airflow
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
github.com
/apache/airflow/pull/69378
patch, web, issue-tracking
-
github.com
/apache/airflow/commit/78abd3044654d44d711eb61e475029fd1b1ccc23
web
-
github.com
/apache/airflow/commit/d08ddc0127d5be7f9b31c1f935bc4d25a897a848
web
-
lists.apache.org
/thread/dm0520yhh4mn7qknyoh45r2w6c5qg2mg
vendor-advisory, web, mailing-list, advisory
-
openwall.com
/lists/oss-security/2026/08/12/6
web, mailing-list, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-59242
advisory, web
-
github.com
/apache/airflow
package
-
github.com
/apache/airflow/releases/tag/3.3.1
web
-
github.com
/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-3992.yaml
web
-
github.com
/advisories/GHSA-fcmm-42r9-mmmm
advisory
Sources
- CVE List CVE-2026-59242
- GitHub Advisory GHSA-fcmm-42r9-mmmm
- NVD CVE-2026-59242
- OSV BIT-airflow-2026-59242
- OSV PYSEC-2026-3992
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