What is CVE-2026-55432?

CVE-2026-55432 is a medium-severity missing authorization vulnerability in github.com/coder/coder/v2 (go), affecting versions >= 2.34.0, < 2.34.2. It is fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17. The application does not perform an authorization check before performing a sensitive operation.

How severe is CVE-2026-55432?

CVE-2026-55432 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of github.com/coder/coder/v2 are affected by CVE-2026-55432?

github.com/coder/coder/v2 (go) versions >= 2.34.0, < 2.34.2 is affected.

Is there a fix for CVE-2026-55432?

Yes. CVE-2026-55432 is fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17. Upgrade to this version or later.

Is CVE-2026-55432 exploitable, and should I be worried?

Whether CVE-2026-55432 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-55432 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-55432?

Upgrade: github.com/coder/coder/v2 to 2.34.2 or later, github.com/coder/coder/v2 to 2.33.8 or later, github.com/coder/coder/v2 to 2.32.7 or later, github.com/coder/coder/v2 to 2.29.17 or later.

CVE-2026-55432 in github.com/coder/coder/v2

Q: How severe is CVE-2026-55432?

CVE-2026-55432 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of github.com/coder/coder/v2 are affected by CVE-2026-55432?

github.com/coder/coder/v2 (go) versions >= 2.34.0, < 2.34.2 is affected.

Q: Is there a fix for CVE-2026-55432?

Yes. CVE-2026-55432 is fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17. Upgrade to this version or later.

Q: Is CVE-2026-55432 exploitable, and should I be worried?

Whether CVE-2026-55432 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-55432 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-55432?

Upgrade: github.com/coder/coder/v2 to 2.34.2 or later, github.com/coder/coder/v2 to 2.33.8 or later, github.com/coder/coder/v2 to 2.32.7 or later, github.com/coder/coder/v2 to 2.29.17 or later.

Summary

Coder's sub-agent app registration bypasses template port-sharing policy enforcement

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.

Workarounds

Disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing.

Resources

Fix: #26061

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22452) for independently disclosing this issue!

Impact

A workspace owner with an agent token could register a sub-agent app as PUBLIC even when the template's MaxPortSharingLevel was owner, exposing the app to unauthenticated users via the wildcard app domain. This affected only deployments using Enterprise port-sharing policy and wildcard app hostnames and required an authenticated workspace owner with an agent token.

The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.

CVE-2026-55432 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.34.2, 2.33.8, 2.32.7, 2.29.17); upgrading removes the vulnerable code path.

Affected versions

github.com/coder/coder/v2 (>= 2.34.0, < 2.34.2) github.com/coder/coder/v2 (>= 2.33.0, < 2.33.8) github.com/coder/coder/v2 (>= 2.30.0, < 2.32.7) github.com/coder/coder/v2 (< 2.29.17)

Security releases

github.com/coder/coder/v2 → 2.34.2 (go) github.com/coder/coder/v2 → 2.33.8 (go) github.com/coder/coder/v2 → 2.32.7 (go) github.com/coder/coder/v2 → 2.29.17 (go)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

Already deployed Kodem?

See it in your environment New to Kodem? Get a demo →

Remediation advice

The fix clamps the sub-agent app sharing level to the template's MaxPortSharingLevel.

The fix was backported to all supported release lines:

Release line	Patched version
2.34	v2.34.2
2.33	v2.33.8
2.32	v2.32.7
2.29 (ESR)	v2.29.17

Frequently Asked Questions

What is CVE-2026-55432? CVE-2026-55432 is a medium-severity missing authorization vulnerability in github.com/coder/coder/v2 (go), affecting versions >= 2.34.0, < 2.34.2. It is fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17. The application does not perform an authorization check before performing a sensitive operation.
How severe is CVE-2026-55432? CVE-2026-55432 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of github.com/coder/coder/v2 are affected by CVE-2026-55432? github.com/coder/coder/v2 (go) versions >= 2.34.0, < 2.34.2 is affected.
Is there a fix for CVE-2026-55432? Yes. CVE-2026-55432 is fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17. Upgrade to this version or later.
Is CVE-2026-55432 exploitable, and should I be worried? Whether CVE-2026-55432 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-55432 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-55432?
- Upgrade github.com/coder/coder/v2 to 2.34.2 or later
- Upgrade github.com/coder/coder/v2 to 2.33.8 or later
- Upgrade github.com/coder/coder/v2 to 2.32.7 or later
- Upgrade github.com/coder/coder/v2 to 2.29.17 or later

Other vulnerabilities in github.com/coder/coder/v2

CVE-IDSeverityPackage summary

GHSA-QRWJ-VH9X-GW5VHighgithub.com/coder/coder/v2: Coder's workspace agent API insecure redirect handling allowed cross-agent file read and write CVE-2026-55438Mediumgithub.com/coder/coder/v2: Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing CVE-2026-55437Mediumgithub.com/coder/coder/v2: Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component CVE-2026-55436Highgithub.com/coder/coder/v2: Coder's AI Bridge Proxy skips TLS certificate verification in default configuration CVE-2026-55435Mediumgithub.com/coder/coder/v2: Suspended Coder users retain access to AI Bridge LLM proxy endpoints