What is CVE-2026-55436?

CVE-2026-55436 is a high-severity security 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.

How severe is CVE-2026-55436?

CVE-2026-55436 has a CVSS score of 7.4 (High). 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-2026-55436?

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

Is there a fix for CVE-2026-55436?

Yes. CVE-2026-55436 is fixed in 2.34.2, 2.33.8, 2.32.7. Upgrade to this version or later.

Is CVE-2026-55436 exploitable, and should I be worried?

Whether CVE-2026-55436 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-2026-55436 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-2026-55436?

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-2026-55436 in github.com/coder/coder/v2

Q: How severe is CVE-2026-55436?

CVE-2026-55436 has a CVSS score of 7.4 (High). 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-2026-55436?

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

Q: Is there a fix for CVE-2026-55436?

Yes. CVE-2026-55436 is fixed in 2.34.2, 2.33.8, 2.32.7. Upgrade to this version or later.

Q: Is CVE-2026-55436 exploitable, and should I be worried?

Whether CVE-2026-55436 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-2026-55436 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-2026-55436?

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

Coder's AI Bridge Proxy skips TLS certificate verification in default configuration

Full technical description

The AI Bridge Proxy (aibridgeproxyd) created a goproxy server whose default transport set InsecureSkipVerify: true and only assigned a secure transport when an upstream proxy was configured. In the default configuration (no upstream proxy), outbound HTTPS to the Coder access URL accepted any TLS certificate.

Note: Practical exploitation requires an on-path (man-in-the-middle) position between the AI Bridge Proxy and the Coder server. Deployments where they are co-located over loopback are effectively unaffected.

Workarounds

Ensure the Coder access URL uses a trusted certificate and secure the network path between the AI Bridge Proxy and the Coder server (for example, loopback or mTLS).

Resources

Fix: #26131

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22455) for independently disclosing this issue!

Impact

An attacker positioned between the proxy and the Coder server, via ARP spoofing, DNS poisoning or control of proxy environment variables, could intercept injected Coder session tokens, user-supplied provider API keys (BYOK) and full request and response bodies including prompts and completions. The default transport also honored HTTP_PROXY and HTTPS_PROXY, allowing environment-based traffic redirection.

CVE-2026-55436 has a CVSS score of 7.4 (High). The vector is network-reachable, no 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 applies the secure transport (TLS 1.2 or higher using system root CAs) unconditionally. The AI Bridge Proxy was introduced in v2.30.0. Earlier release lines including the v2.29 ESR line are 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-2026-55436? CVE-2026-55436 is a high-severity security 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.
How severe is CVE-2026-55436? CVE-2026-55436 has a CVSS score of 7.4 (High). 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-2026-55436? github.com/coder/coder/v2 (go) versions >= 2.34.0, < 2.34.2 is affected.
Is there a fix for CVE-2026-55436? Yes. CVE-2026-55436 is fixed in 2.34.2, 2.33.8, 2.32.7. Upgrade to this version or later.
Is CVE-2026-55436 exploitable, and should I be worried? Whether CVE-2026-55436 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-2026-55436 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-2026-55436?
- 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-2026-55435Mediumgithub.com/coder/coder/v2: Suspended Coder users retain access to AI Bridge LLM proxy endpoints CVE-2026-55434Mediumgithub.com/coder/coder/v2: Coder vulnerable to denial of service via unbounded request body in AI Bridge provider endpoints