CVE-2026-33858 json
Apache Airflow: Unsafe Deserialization via Legacy Serialization Keys (__type/__var) Bypass in XCom API
published 2026-04-13 6 mo ago modified 2026-11-03 6 d ago also BIT-airflow-2026-33858 , EUVD-2026-21978 , GHSA-mc4f-r875-v87w , PYSEC-2026-20
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 48%
- public exploits
- 0
- none known
Summary
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 trusted, severity of this issue is Low.
Users are recommended to upgrade to Apache Airflow 3.2.0, which resolves this issue.
Patch / fix
- pypi apache-airflow 3.2.0
- bitnami airflow 3.2.0
- Apache Software Foundation Apache Airflow 3.2.0
- github.com/apache/airflow#64148 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 6 mo ago
Exploit prediction
0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| OSV | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | apache-airflow | >=3.1.8, <3.2.0 |
3.2.0 |
| bitnami | airflow | >=3.1.8, <3.2.0 |
3.2.0 |
Affected products
- Apache Software Foundation Apache Airflow
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
github.com
/apache/airflow/pull/64148
patch, web, issue-tracking, report
-
lists.apache.org
/thread/1npt3o2x81s0gw9tmfcv4n7p1z9hdmy0
vendor-advisory, web, mailing-list, advisory
-
openwall.com
/lists/oss-security/2026/04/13/7
web, mailing-list, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-33858
advisory, web
-
github.com
/apache/airflow
package
-
github.com
/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-20.yaml
web
-
github.com
/advisories/GHSA-mc4f-r875-v87w
advisory
Sources
- CVE List CVE-2026-33858
- GitHub Advisory GHSA-mc4f-r875-v87w
- NVD CVE-2026-33858
- OSV BIT-airflow-2026-33858
- OSV PYSEC-2026-20
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.