CVE-2025-27616 Overview
CVE-2025-27616 affects Vela, a Pipeline Automation (CI/CD) framework built on Linux container technology and written in Go. The vulnerability allows an authenticated attacker to spoof a webhook payload using a specific set of headers and body data. This spoofed payload transfers ownership of a repository and its repo-level secrets to a separate repository controlled by the attacker.
The flaw is categorized under [CWE-290]: Authentication Bypass by Spoofing. Any user with access to the Vela instance and the linked source control manager can perform the exploit. Follow-up builds against the attacker's repository exfiltrate the transferred secrets. Versions 0.25.3 and 0.26.3 remediate the issue.
Critical Impact
Attackers with low-privileged access can hijack repository ownership and exfiltrate CI/CD secrets through spoofed webhook payloads, exposing credentials that unlock downstream production systems.
Affected Products
- go-vela/server versions prior to 0.25.3 (0.25.x branch)
- go-vela/server versions prior to 0.26.3 (0.26.x branch)
- Vela CI instances with enabled repositories holding repo-level CI secrets
Discovery Timeline
- 2025-03-10 - CVE-2025-27616 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-27616
Vulnerability Analysis
Vela integrates with source control managers and processes inbound webhook events to trigger pipeline builds. The server trusts webhook payload fields to identify the source repository and route ownership state. When repository metadata within the payload is not sufficiently validated against the authenticated source, the server accepts a crafted payload as legitimate.
An attacker with access to the CI instance and the linked source control manager crafts a webhook request that impersonates a legitimate delivery. The server updates the repository record so that ownership associations, including access to repo-level secrets, move to the attacker's repository. Subsequent pipeline executions triggered from the attacker's repository can inject those secrets into build steps, enabling exfiltration to attacker-controlled infrastructure.
Root Cause
The root cause is insufficient authentication of webhook source integrity. Vela's server relied on payload-controlled headers and body data to associate incoming events with a repository record, without cryptographically binding the event to the originating repository. This allowed a client-side crafted payload to satisfy server-side ownership checks. See the GitHub Security Advisory GHSA-9m63-33q3-xq5x for details.
Attack Vector
The attack is delivered over the network to the Vela server's webhook ingestion endpoint. The attacker requires low-privilege access to the CI instance and to the linked source control manager. The attacker submits a crafted webhook request whose headers and body identify the victim repository, causing the server to move ownership. Once ownership is transferred, the attacker triggers pipeline builds in the attacker's repository to receive the previously scoped secrets.
Exploit code has not been publicly released. Refer to remediation commits 257886e and 67c1892 for the specific validation logic added by maintainers.
Detection Methods for CVE-2025-27616
Indicators of Compromise
- Unexpected changes to repository ownership records in the Vela database, particularly outside of routine administrative windows.
- Webhook deliveries whose payload repository identifier does not match the source control manager account tied to the request.
- New or modified pipeline definitions on repositories immediately following an ownership change event.
- Outbound network connections from build runners to previously unseen destinations following secret access.
Detection Strategies
- Audit Vela server logs for POST requests to webhook endpoints that result in repository ownership state transitions.
- Correlate source control manager audit events with Vela ownership changes to identify mismatched actors.
- Alert on repo-level secret access from pipeline builds executed under a newly assigned owning repository.
Monitoring Recommendations
- Ingest Vela server access logs and application logs into a centralized logging pipeline for retention and correlation.
- Monitor for anomalous build execution patterns, including builds that read secrets and then perform external HTTP requests.
- Track version metadata of running Vela server instances and flag any instance below 0.25.3 or 0.26.3.
How to Mitigate CVE-2025-27616
Immediate Actions Required
- Upgrade Vela server to version 0.25.3 or 0.26.3 depending on the deployed release branch.
- Rotate all repo-level CI secrets that were accessible on any Vela instance prior to patching.
- Review repository ownership records for unauthorized transfers occurring before the upgrade.
- Restrict access to the Vela instance and the linked source control manager to trusted users only.
Patch Information
Maintainers released fixes in go-vela/server v0.25.3 and go-vela/server v0.26.3. The remediation is implemented in commits 257886e and 67c1892, which strengthen webhook payload validation to prevent spoofed ownership transfers.
Workarounds
- No workarounds are available per the vendor advisory. Upgrading to a fixed release is the only supported remediation path.
- As a temporary compensating control, restrict Vela user accounts and audit secret usage until the patched version is deployed.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
