What is CVE-2026-55435?

CVE-2026-55435 is a medium-severity incorrect 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. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.

How severe is CVE-2026-55435?

CVE-2026-55435 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-2026-55435?

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

Is there a fix for CVE-2026-55435?

Yes. CVE-2026-55435 is fixed in 2.34.2, 2.33.8, 2.32.7. Upgrade to this version or later.

Is CVE-2026-55435 exploitable, and should I be worried?

Whether CVE-2026-55435 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-2026-55435 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-2026-55435?

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.

CVE-2026-55435 in github.com/coder/coder/v2

Q: How severe is CVE-2026-55435?

CVE-2026-55435 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-2026-55435?

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

Q: Is there a fix for CVE-2026-55435?

Yes. CVE-2026-55435 is fixed in 2.34.2, 2.33.8, 2.32.7. Upgrade to this version or later.

Q: Is CVE-2026-55435 exploitable, and should I be worried?

Whether CVE-2026-55435 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-2026-55435 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-2026-55435?

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.

Summary

Suspended Coder users retain access to AI Bridge LLM proxy endpoints

Full technical description

AI Bridge proxy endpoints authenticate via Server.IsAuthorized in coderd/aibridgedserver, which validates key format, expiry, secret and deleted or system users but does not check whether the account is suspended. Because suspension does not revoke existing API keys, a suspended user's unexpired token keeps working.

Note: Practical impact is limited to already-issued API keys of suspended users until those keys are deleted.

Workarounds

On suspension, delete the user's API keys via DELETE /api/v2/users/{user}/keys.

Resources

Fix: #26173

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22446) for independently disclosing this issue!

Impact

A suspended user with a previously issued long-lived token could continue calling AI Bridge LLM proxy endpoints, consuming paid provider resources billed to the deployment and, if injected MCP tools are enabled, invoking those tools. Access persists until the token expires, which may be months after suspension.

The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.

CVE-2026-55435 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); 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)

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)

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.

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Remediation advice

The fix makes AI Bridge authorization reject non-active users like the standard API key middleware. AI Bridge was introduced in v2.30.0. The v2.29 ESR line is not affected.

The fix is available in the following releases:

Release line	Patched version
2.34	v2.34.2
2.33	v2.33.8
2.32	v2.32.7

Frequently Asked Questions

What is CVE-2026-55435? CVE-2026-55435 is a medium-severity incorrect 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. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
How severe is CVE-2026-55435? CVE-2026-55435 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-2026-55435? github.com/coder/coder/v2 (go) versions >= 2.34.0, < 2.34.2 is affected.
Is there a fix for CVE-2026-55435? Yes. CVE-2026-55435 is fixed in 2.34.2, 2.33.8, 2.32.7. Upgrade to this version or later.
Is CVE-2026-55435 exploitable, and should I be worried? Whether CVE-2026-55435 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-2026-55435 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-2026-55435?
- 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

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-2026-55434Mediumgithub.com/coder/coder/v2: Coder vulnerable to denial of service via unbounded request body in AI Bridge provider endpoints