What is the CVSS score of EUVD-2026-21978?

EUVD-2026-21978 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Apache are affected by EUVD-2026-21978?

Apache Airflow versions 3.1.8 through 3.1.x contain a remote code execution vulnerability in XCom payload handling that allows authenticated DAG Authors to execute arbitrary code within the webserver…. A patch is available.

How to fix or mitigate EUVD-2026-21978?

Within 24 hours: inventory all Apache Airflow 3.1.8 through 3.1.x deployments and identify DAG Author role assignments. Within 7 days: upgrade to Apache Airflow 3.2.0 or apply vendor-released patch; if immediate upgrade is not feasible, implement access controls restricting DAG Author role to essential personnel only and enable detailed audit logging of DAG creation and modification activities. Within 30 days: conduct post-patch validation and review DAG Author access provisioning across all environments.

Apache EUVD-2026-21978

| CVE-2026-33858 HIGH

Deserialization of Untrusted Data (CWE-502)

2026-04-13 apache

GHSA-mc4f-r875-v87w

Deserialization Apache RCE

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Re-analysis Queued

Apr 17, 2026 - 15:22 vuln.today

cvss_changed

Analysis Generated

Apr 15, 2026 - 12:30 vuln.today

CVSS changed

Apr 13, 2026 - 16:22 NVD

8.8 (HIGH)

EUVD ID Assigned

Apr 13, 2026 - 15:15 euvd

EUVD-2026-21978

Analysis Generated

Apr 13, 2026 - 15:15 vuln.today

Patch released

Apr 13, 2026 - 15:15 nvd

Patch available

CVE Published

Apr 13, 2026 - 14:36 nvd

HIGH 8.8

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

21 pypi packages depend on apache-airflow (11 direct, 10 indirect)

Ecosystem-wide dependent count for version 3.1.8.

DescriptionCVE.org

Dag Authors, who normally should not be able to execute code in the webserver context could craft XCom payload causing the webserver to execute arbitrary code. Since Dag Authors are already highly trusted, severity of this issue is Low.

Users are recommended to upgrade to Apache Airflow 3.2.0, which resolves this issue.

AnalysisAI

Remote code execution in Apache Airflow 3.1.x allows authenticated DAG Authors to execute arbitrary code in the webserver context through crafted XCom payloads exploiting insecure deserialization (CWE-502). Affects Apache Airflow versions 3.1.8 through <3.2.0. Despite CVSS 8.8, vendor rates severity as Low due to DAG Authors being highly trusted roles. No public exploit identified at time of analysis, with EPSS exploitation probability at 0.07% (21st percentile), indicating minimal real-world risk. Vendor-released patch: Apache Airflow 3.2.0.

Technical ContextAI

Apache Airflow's XCom (cross-communication) mechanism allows tasks to exchange messages and data between workflow executions. The vulnerability stems from insecure deserialization (CWE-502) when processing XCom payloads. DAG (Directed Acyclic Graph) Authors-users with permissions to create and modify workflow definitions-can craft malicious serialized objects within XCom payloads. When the Airflow webserver deserializes these payloads, it triggers arbitrary code execution in the webserver's runtime context. The affected component (cpe:2.3:a:apache_software_foundation:apache_airflow) processes user-supplied serialized data without adequate validation, allowing trusted but potentially malicious insiders to escalate privileges from DAG authoring permissions to full webserver code execution capabilities. This is a classic insecure deserialization vulnerability where application trust boundaries fail to account for malicious data from authenticated sources.

RemediationAI

Upgrade to Apache Airflow 3.2.0, which fully resolves the insecure deserialization issue in XCom payload handling. The upstream fix is implemented in GitHub pull request #64148 (https://github.com/apache/airflow/pull/64148). Organizations running any Apache Airflow 3.1.x version should prioritize migration to 3.2.0 following standard change management procedures. Review DAG Author role assignments and audit XCom usage patterns during the upgrade window to identify any anomalous activity. No workarounds are documented; patching to 3.2.0 is the only remediation path. Consult the official Apache advisory at https://lists.apache.org/thread/1npt3o2x81s0gw9tmfcv4n7p1z9hdmy0 for deployment-specific guidance and release notes.