dbcve.org
Missing AuthorizationWeakness · CWE-862

CVE-2026-56280

HIGH · 7.1 CVSS v3.1 Published 2026-06-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Cap-go before 12.128.2 contains a privilege inversion vulnerability in GET /build/logs/:jobId that allows read-only API key holders to cancel running native builds. The endpoint registers an abort listener on the SSE stream that unconditionally invokes cancelBuildOnDisconnect() using the privileged server-side BUILDER_API_KEY when clients disconnect, bypassing the app.build_native permission check required by the explicit POST /build/cancel/:jobId endpoint. Attackers with read-only API keys can repeatedly disrupt native build operations and CI/CD workflows by opening the log stream and dropping the connection.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Cap-go before 12.128.2 has a privilege inversion in the GET /build/logs/:jobId endpoint where an SSE stream abort listener unconditionally calls cancelBuildOnDisconnect() using the privileged server-side BUILDER_API_KEY, bypassing the app.build_native permission check that the explicit POST /build/cancel/:jobId endpoint properly enforces. Attackers with read-only API keys can trigger build cancellations by opening the log stream and disconnecting.

MitigationEnsure the SSE abort listener respects the same authorization checks as the explicit cancel endpoint, or remove the auto-cancel-on-disconnect behavior for unprivileged users, requiring explicit permission checks before invoking build cancellation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Cap-go installed version
    Run `cap-go --version` or check the package.json/version file in the Cap-go installation directory. Compare the version number to 12.128.2.
    Affected if Version is before 12.128.2 (e.g., 12.128.1, 12.120.0, etc.)
  2. Verify read-only API key access to build logs endpoint
    Use a read-only API key (not a builder key) to make a GET request to /build/logs/:jobId. Confirm the request is accepted and an SSE stream begins.
    Affected if Read-only API keys can access GET /build/logs/:jobId endpoint
  3. Confirm POST /build/cancel endpoint authorization
    Test POST /build/cancel/:jobId with a read-only API key. The endpoint should reject the request with a 403 Forbidden due to missing app.build_native permission.
    Affected if POST /build/cancel/:jobId properly enforces permission but GET /build/logs/:jobId does not (inconsistency indicates the flaw)
  4. Inspect SSE abort listener configuration
    Review Cap-go server source code or configuration for the GET /build/logs/:jobId endpoint handler. Look for an abort event listener that calls cancelBuildOnDisconnect() or similar cancellation logic.
    Affected if SSE stream abort listener exists and invokes build cancellation without permission checks
  5. Check BUILDER_API_KEY usage in abort handler
    Examine the SSE abort listener code path to verify it uses the privileged server-side BUILDER_API_KEY rather than respecting the requesting user's permissions.
    Affected if Abort listener uses privileged BUILDER_API_KEY unconditionally

You are affected if you run Cap-go version before 12.128.2 AND your read-only API keys can trigger build cancellations via the SSE log stream disconnect behavior.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Ensure the SSE abort listener respects the same authorization checks as the explicit cancel endpoint, or remove the auto-cancel-on-disconnect behavior for unprivileged users, requiring explicit permission checks before invoking build cancellation.

Recommended fix Moderate confidence

Cap-go 12.128.2 or later

  1. Upgrade Cap-go to version 12.128.2 or later to resolve the privilege inversion vulnerability in the GET /build/logs/:jobId endpoint.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-56280 in production — separate from our analysis above.

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