CVE-2026-55432: Coder's sub-agent app registration bypasses template port-sharing policy enforcement

July 6, 2026

The CreateSubAgent RPC did not validate a requested app sharing level against the template’s MaxPortSharingLevel before persisting workspace apps, letting a workspace owner exceed the administrator’s configured maximum.

Note: Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls.

References

github.com/advisories/GHSA-x9qq-2qh5-8rxf
github.com/coder/coder/pull/26061
github.com/coder/coder/security/advisories/GHSA-x9qq-2qh5-8rxf
nvd.nist.gov/vuln/detail/CVE-2026-55432

Code Behaviors & Features

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