CVE-2026-68076: 
Homebrew Schwachstellenanalyse und -minderung

CVE-2026-68076 is an authorization bypass vulnerability in Apache Airflow's environment-variable secrets backend that allows an authenticated user of one team to resolve another team's Connection or Variable in multi-team mode. The flaw affects all Apache Airflow versions prior to 3.3.1 and was disclosed on August 12, 2026. It carries a CVSS v3.1 base score of 5.4 (Medium), classified under CWE-639 (Authorization Bypass Through User-Controlled Key) (Github Advisory, Apache Advisory).

The root cause is a defective guard (_is_team_specific_accessed_as_global) in Airflow's environment-variable secrets backend (CWE-639). The guard had two critical gaps: its regex pattern _[^_]+___.+ could not match team names containing underscores (which are permitted by the ^[a-zA-Z0-9_-]{3,50}$ naming rule), and it only executed when no team scope was supplied — meaning it was entirely skipped when a team context was active. When the guard failed to apply, a missed team-scoped lookup fell through to an unconditional os.environ.get(PREFIX + id.upper()) call, which resolved the stored AIRFLOW_CONN__<TEAM>___<ID> environment variable regardless of which team initiated the request. A secondary ambiguity exists because a team name may itself contain the ___ separator, making the environment variable name for one team's connection byte-identical to another team's, exploitable even through the team-scoped lookup path (GitHub PR #70736, GitHub PR #70902).

An authenticated user belonging to one team can trigger POST /api/v2/connections/test to resolve and use another team's stored credentials (Connections and Variables) without those credentials being directly returned to the attacker — the endpoint authenticates outward using the resolved credentials. This constitutes a cross-team credential abuse scenario with low confidentiality impact (credentials are used, not directly exposed) and low availability impact. The vulnerability is scoped to multi-team Airflow deployments where team-scoped secrets are provisioned as environment variables, limiting the blast radius to such configurations (Github Advisory, Apache Advisory).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation as of the disclosure date (Github Advisory). The EPSS score is approximately 0.22–0.34%, placing it in the lower percentiles for near-term exploitation likelihood. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires a specific non-default configuration: [core] multi_team must be enabled, [core] test_connection must be explicitly set to Enabled (it ships as Disabled), team-scoped secrets must be provisioned as environment variables in the API-server process, and the attacker must know the encoded connection identifier of the target team (Apache Advisory).

1. Reconnaissance: Identify an Apache Airflow deployment running a version prior to 3.3.1 with [core] multi_team = True and [core] test_connection = Enabled configured.
2. Authenticate: Log in to the Airflow API as a legitimate user belonging to any team within the multi-team deployment.
3. Enumerate target connection identifier: Determine or guess the encoded identifier of a Connection belonging to another team. The environment variable follows the pattern AIRFLOW_CONN__<TEAM>___<ID> (uppercased). Knowledge of team names and connection IDs — particularly those with underscores in the team name — is required.
4. Craft the API request: Send a POST /api/v2/connections/test request supplying the target team's connection identifier. Due to the guard bypass, the secrets backend resolves the other team's environment variable instead of the caller's own.
5. Trigger cross-team credential use: The API endpoint uses the resolved credentials to authenticate outward to the configured external service (e.g., a database or cloud provider), effectively acting as the target team without directly returning the credential value to the attacker (Github Advisory, GitHub PR #70736).

• Logs: Airflow API server logs showing POST /api/v2/connections/test requests from users whose team does not match the team namespace embedded in the connection identifier being tested; repeated test-connection calls targeting connection IDs with underscore-containing team prefixes.
• Network: Outbound authentication attempts to external services (databases, cloud APIs, etc.) initiated by the Airflow API server process that do not correspond to the requesting user's team's expected connections.
• Configuration Audit: Presence of both [core] multi_team = True and [core] test_connection = Enabled in airflow.cfg, combined with team-scoped secrets provisioned as AIRFLOW_CONN__<TEAM>___<ID> environment variables in the API-server process environment.

Upgrade to apache-airflow 3.3.1 or later, which contains fixes from PRs #70736 and #70902 that invert the lookup order, widen the separator check, and refuse any secret ID containing the ___ separator before either lookup path (Apache Advisory, GitHub PR #70736). If immediate upgrade is not possible, set [core] test_connection = Disabled (the default) to block the vulnerable endpoint entirely. Additionally, review whether team-scoped secrets must be provisioned as environment variables in the API-server process, and consider migrating to an alternative secrets backend to reduce exposure.