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Woodpecker: Privilege escalation via unrestricted serviceAccountName in the Kubernetes backend

High severity GitHub Reviewed Published Jul 1, 2026 in woodpecker-ci/woodpecker • Updated Jul 14, 2026

Package

gomod github.com/woodpecker-ci/woodpecker (Go)

Affected versions

>= 1.0.0, <= 1.0.4

Patched versions

None
gomod go.woodpecker-ci.org/woodpecker/v2 (Go)
<= 2.8.3
None
gomod go.woodpecker-ci.org/woodpecker/v3 (Go)
< 3.16.0
3.16.0

Description

Impact

A privilege escalation vulnerability affects Woodpecker instances using the Kubernetes backend.

The pipeline option backend_options.kubernetes.serviceAccountName was passed directly to the pod spec without any admin gating.

Who is impacted: any operator running the Kubernetes backend. Any user with Push permission on a connected repository can run pipeline pods under an arbitrary ServiceAccount in the pipeline namespace, gaining that account's RBAC permissions. If a privileged ServiceAccount is reachable in that namespace, this can lead to secret exfiltration (database credentials, API keys, TLS certs) and full cluster takeover.

Patches

woodpecker-ci/woodpecker#6792

Workarounds

Operators who cannot upgrade immediately can mitigate by any of:

  • Restrict Push access on repositories connected to the Kubernetes-backed instance to
    trusted users only.
  • Harden the pipeline namespace: ensure no privileged ServiceAccount exists or is bound in
    the namespace where pipeline pods run; keep the default ServiceAccount minimally privileged.
  • Disable ServiceAccount token automounting for ServiceAccounts that should not be used by
    pipelines.
  • Enforce an admission policy (e.g. OPA/Gatekeeper, Kyverno, or a ValidatingAdmissionPolicy)
    that rejects pipeline pods setting an unexpected serviceAccountName.
  • Use a dedicated, isolated namespace per org/instance with no sensitive RBAC bindings.

Resources

  • Vulnerable option introduced in commit 609ba481b5e912f59aaae8ca7bc22b44523c5e37
  • Affected versions: v1.0.0 through v3.15.0
  • Source: pipeline/backend/kubernetes/backend_options.go (field ServiceAccountName),
    pipeline/backend/kubernetes/pod.go (assigned to pod spec with no gating)

References

@6543 6543 published to woodpecker-ci/woodpecker Jul 1, 2026
Published to the GitHub Advisory Database Jul 14, 2026
Reviewed Jul 14, 2026
Last updated Jul 14, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS score

Weaknesses

Improper Privilege Management

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. Learn more on MITRE.

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Learn more on MITRE.

CVE ID

CVE-2026-61549

GHSA ID

GHSA-qf34-295c-26v8

Source code

Credits

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