PYSEC-2026-3989 BIT-airflow-2026-82355 CVE-2026-82355
When a request to the Airflow core API carries both a session cookie and an explicit `Authorization: Bearer` token, Airflow resolves the caller from the cookie…
- Severity
- 4.2 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.73%
- Chance of exploitation in the next 30 days. Higher than 54.45% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-384 Session Fixation
- Fix
- None yet
- No fixed version published
Description
When a request to the Airflow core API carries both a session cookie and an explicit Authorization: Bearer token, Airflow resolves the caller from the cookie and ignores the bearer token, inverting the intended precedence of bearer over cookie. The request then executes -- and is recorded in the audit log -- as the cookie's principal rather than the identity the client explicitly presented.
Only Apache Airflow 3.3.0 and 3.3.1 are affected. Earlier releases do not contain the code path that caches the cookie-derived user, and are not vulnerable.
Exploiting this requires an attacker to first place a valid session cookie of their own into the victim's browser or client: for example by cookie tossing from a sibling subdomain, through cross-site scripting in a separate application sharing a parent domain, or via a shared workstation. Deployments that host the Airflow UI on a domain shared with other applications are therefore the most exposed; a deployment on a dedicated domain with no co-hosted applications is not reachable this way. The consequence is principal confusion and misattributed audit records rather than a direct privilege escalation.
Users of 3.3.0 or 3.3.1 should upgrade to Apache Airflow 3.3.2 or later, which resolves the caller from the explicitly supplied credential whenever one is present.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| apache-airflow | <= 3.3.0<= 3.3.1 |
No fix yet |
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 3.1 4.2
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Weakness
CWE-384: Session Fixation
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
How to prevent it
- Architecture and Design: Invalidate any existing session identifiers prior to authorizing a new user session.
- Architecture and Design: For platforms such as ASP that do not generate new values for sessionid cookies, utilize a secondary cookie. In this approach, set a secondary cookie on the user's browser to a random value and set a session variable to the same value. If the session variable and the cookie value ever don't match, invalidate the session, and force the user to log on again.
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
References
Advisories
Fixes and patches
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| CVE-2020-13927 Authentication bypass in Apache Airflow | Critical Known exploited | Also affects apache-airflow |
| CVE-2020-11978 Remote code execution (RCE) in Apache Airflow | High Known exploited | Also affects apache-airflow |
| PYSEC-2026-3990 Apache Airflow: the Core API logout endpoint revokes only a session token presented as the _token cookie. | Critical | Also affects apache-airflow |
| PYSEC-2026-3988 Apache Airflow's `/assets/events` API returned asset events for every Dag in the deployment, with no filter restricting them to the Dags the caller is… | Medium | Also affects apache-airflow |
| GHSA-5247-m8w9-2v4m Apache Airflow missing team context permits cross-team Dag actions and XCom reads | Medium | Also affects apache-airflow |
| GHSA-f3c2-j7g8-vpp8 Apache Airflow Task SDK fails to mask list-shaped JSON Variables | Medium | Also affects apache-airflow |
| GHSA-cjv4-7hp2-2x9h Apache Airflow bulk endpoints log Variable and Connection secrets in cleartext | Medium | Also affects apache-airflow |
| GHSA-j4jc-cq9h-xrhr Apache Airflow Backfill API parser discrepancy permits cross-DAG authorization bypass | High | Also affects apache-airflow |
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