CVE-2026-56280

high

Description

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.

References

https://www.vulncheck.com/advisories/cap-go-privilege-inversion-in-build-log-stream-via-sse-disconnect

https://github.com/Cap-go/capgo/security/advisories/GHSA-95g7-xwwx-j737

Details

Source: Mitre, NVD

Published: 2026-06-22

Updated: 2026-06-22

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:C

Severity: High

CVSS v3

Base Score: 7.1

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

Severity: High

CVSS v4

Base Score: 7.1

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

Severity: High