Which versions of Cap-go Capgo are affected by CVE-2026-56280?

Cap-go (Capgo) deployments before version 12.128.2 are vulnerable to a privilege escalation flaw that allows attackers with basic API credentials to disrupt running native builds, creating a…. A patch is available.

How to fix or mitigate CVE-2026-56280?

Within 24 hours: Identify all Capgo deployments and current versions in use; query API audit logs for suspicious build cancellations or repeated disconnections from the GET /build/logs/:jobId endpoint. Within 7 days: Rotate all read-only Capgo API keys; implement network segmentation to restrict access to build-log endpoints from trusted CI/CD systems only; enable alerting on unexpected build cancellations. Within 30 days: Deploy compensating controls listed below; contact Capgo vendor support for estimated patch release timeline; evaluate temporary restriction of read-only API key distribution to non-essential services.

Cap-go Capgo CVE-2026-56280

Q: What is the CVSS score of CVE-2026-56280?

CVE-2026-56280 has a CVSS 4.0 base score of 7.1 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.3%.

EUVD-2026-38368 HIGH

Missing Authorization (CWE-862)

2026-06-22 VulnCheck

Authentication Bypass Cap Go Capgo

7.1

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

7.1 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

7.1 HIGH

Remote, low-complexity, requires a low-privilege read-only API key (PR:L), no UI; high availability impact from build cancellation, limited integrity, no confidentiality loss.

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

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Patch available

Jun 22, 2026 - 23:02 EUVD

Analysis Generated

Jun 22, 2026 - 22:17 vuln.today

DescriptionCVE.org

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.

AnalysisAI

Privilege inversion in Cap-go (Capgo) before 12.128.2 lets holders of read-only API keys cancel running native builds by abusing the GET /build/logs/:jobId SSE endpoint. On client disconnect the server invokes cancelBuildOnDisconnect() using the privileged BUILDER_API_KEY, bypassing the app.build_native permission enforced on POST /build/cancel/:jobId. No public exploit identified at time of analysis, but the issue is trivially reproducible against any deployment exposing the log stream.

Technical ContextAI

Capgo is an open-source mobile live-update and native build service for Capacitor apps; the affected component is its build/log streaming API delivered over Server-Sent Events. The root cause is CWE-862 (Missing Authorization): the abort listener attached to the SSE stream is wired to a privileged internal action (build cancellation) using the server's BUILDER_API_KEY rather than the caller's identity, so authorization on the cancel path is effectively skipped. The affected CPE (cpe:2.3:a:cap-go:capgo:*) covers all Capgo versions prior to 12.128.2, where the disconnect handler unconditionally calls the privileged cancel function instead of re-checking the app.build_native permission tied to the caller.

RemediationAI

Upgrade Capgo to version 12.128.2 or later, where the disconnect handler enforces the app.build_native permission against the caller's identity rather than invoking the privileged BUILDER_API_KEY path; details are in the vendor advisory at https://github.com/Cap-go/capgo/security/advisories/GHSA-95g7-xwwx-j737. Until the upgrade is applied, audit and rotate any read-only API keys that are not strictly necessary, restrict network access to the /build/logs/:jobId endpoint at the reverse proxy or WAF layer (allowing only trusted CI/CD orchestrators), and monitor build-cancellation events for unexpected sources - noting that proxy-level blocking will also break legitimate log streaming for affected clients.