How severe is CVE-2023-40273?

CVE-2023-40273 has a CVSS score of 8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-40273?

CVE-2023-40273 affects the following packages: apache-airflow (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2023-40273?

Update apache-airflow to 2.7.0rc2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40273 is resolved across your whole dependency graph.

How do I detect CVE-2023-40273 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for apache-airflow. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-40273 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2023-40273?

O3 pinpoints whether CVE-2023-40273 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-40273 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-40273 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-40273?

CVE-2023-40273 has an EPSS (Exploit Prediction Scoring System) score of 1.4%, placing it in the 68th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-40273 published, and has it been updated?

CVE-2023-40273 was published on August 23, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-40273: Apache Airflow Session Fixation vulnerability…

EPSS Exploitation Probability

via FIRST.org ↗

1.4%probability of exploitation in next 30 days

Lower Risk68th percentile+1.09%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐍apache-airflow

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

The session fixation vulnerability allowed the authenticated user to continue accessing Airflow webserver even after the password of the user has been reset by the admin - up until the expiry of the session of the user. Other than manually cleaning the session database (for database session backend), or changing the secure_key and restarting the webserver, there were no mechanisms to force-logout the user (and all other users with that).

With this fix implemented, when using the database session backend, the existing sessions of the user are invalidated when the password of the user is reset. When using the securecookie session backend, the sessions are NOT invalidated and still require changing the secure key and restarting the webserver (and logging out all other users), but the user resetting the password is informed about it with a flash message warning displayed in the UI. Documentation is also updated explaining this behaviour.

Users of Apache Airflow are advised to upgrade to version 2.7.0 or newer to mitigate the risk associated with this vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`apache-airflow`	all versions	2.7.0rc2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for apache-airflow. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update apache-airflow to 2.7.0rc2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40273 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-40273 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-40273. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

The session fixation vulnerability allowed the authenticated user to continue accessing Airflow webserver even after the password of the user has been reset by the admin - up until the expiry of the session of the user. Other than manually cleaning the session database (for database session backend), or changing the secure_key and restarting the webserver, there were no mechanisms to force-logout the user (and all other users with that). With this fix implemented, when using the database session backend, the existing sessions of the user are invalidated when the password of the user is reset.

O3 Security · Impact-Aware SCA

Is CVE-2023-40273 in your dependencies?

O3 detects CVE-2023-40273 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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CVE-2023-40273