CVE-2021-35936No Authentication on Logging Server
- 5.3MediumCVSS base score
- 5.5%Exploitation in 30 daysEPSS · top 7.1% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
If remote logging is not used, the worker (in the case of CeleryExecutor) or the scheduler (in the case of LocalExecutor) runs a Flask logging server and is listening on a specific port and also binds on 0.0.0.0 by default. This logging server had no authentication and allows reading log files of DAG jobs. This issue affects Apache Airflow < 2.1.2.
Timeline
ID reserved
By apache
- 48 days later
· 48 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 5.5% · top 7.1% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
Apache Software Foundation · Apache Airflow
- affected Apache Airflow – < 2.1.2
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIapache-airflowGHSA-m6h2-jx9v-58w6 (opens in a new tab)
What to do
Workaround: Use remote logging with GCS, S3, Elasticsearch etc. This is recommended for production environments. And do not publicly expose any other ports apart from Webserver port, Flower port etc.
References
References1
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-0013 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-m6h2-jx9v-58w6 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-35936)Record last updated .