CVE-2026-42359: A bug in Apache Airflow's XCom PATCH endpoint `PATCH /api/v2/xcomEntries/{key}` allowed an authenticated UI/AP

This month

HIGH 8.8WATCHLISTUPGRADE

CVE-2026-42359 is a high-severity flaw (CVSS 8.8) affecting airflow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A bug in Apache Airflow's XCom PATCH endpoint `PATCH /api/v2/xcomEntries/{key}` allowed an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e.g. `return_value`) that the matching POST endpoint already validated against `FORBIDDEN_XCOM_KEYS`. The endpoint also accepted serialized payload shapes the triggerer's deserializer treats as code; combined, this allowed RCE on the triggerer when th

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-06-01
Last modified	2026-07-21

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-07-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-01 09:16 UTCPublished CVE record published
2026-07-21 19:10 UTCUpdated Record last modified

apache airflow UPGRADE

Affected: >= 3.2.0 and < 3.2.2

Fixed in: 3.2.2

Safe to downgrade to: a release before 3.2.0

1. Check installed version

apt-cache policy airflow || rpm -q airflow || airflow --version

2. UPGRADE to 3.2.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade airflow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade airflow

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.2.0 (Debian / Ubuntu)

apt-cache madison airflow sudo apt install airflow=<VERSION_BEFORE_3.2.0> sudo apt-mark hold airflow

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list airflow sudo dnf downgrade airflow-<VERSION_BEFORE_3.2.0> sudo dnf versionlock add airflow

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42359?

airflow: upgrade to 3.2.2. Exact commands for each OS are on this page.

Is CVE-2026-42359 being exploited?

CVE-2026-42359 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42359 affect?

CVE-2026-42359 affects airflow. Severity is high (CVSS 8.8). A bug in Apache Airflow's XCom PATCH endpoint `PATCH /api/v2/xcomEntries/{key}` allowed an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e.g. `return_value`) that the matching PO

How urgent is CVE-2026-42359?

Priority 48/100. High severity; On your watchlist

Software pages

Apache Airflow vulnerabilities

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References

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