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

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-08 · updated 2026-07-08
Weakness: CWE-862

Description

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, 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. Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2clamps the sub-agent app sharing level to the template's `MaxPortSharingLevel`. As a workaround, disable wildcard app hostnames (`CODER_WILDCARD_ACCESS_URL`) to block subdomain-based app routing.

Affected products

coder: before 2.29.17; from 2.30.0 before 2.32.7; from 2.33.0 before 2.33.8; from 2.34.0 before 2.34.2 — fixed in 2.29.17, 2.32.7, 2.33.8, 2.34.2

How to fix

Upgrade to a fixed version: coder 2.29.17, 2.32.7, 2.33.8, 2.34.2. Check the vendor advisory for mitigations.

References

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