Vulnerability in Apache Airflow

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 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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (54.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-82355: held from 0.007 to 0.007.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-82355?
CVE-2026-82355 is a medium-severity vulnerability in Apache Airflow, classified under Session Fixation. CVSS score: 4.2/10. Published 2026-09-21.
How severe is CVE-2026-82355?
Medium severity. CVSS v3 base score is 4.2 out of 10.