CVE-2026-55436: coder Cert Validation Flaw — Fix

Description

Coder allows organizations to provision remote development environments via Terraform. Starting in version 2.30.0 and prior to versions 2.32.7, 2.33.8, and 2.34.2, 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. 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. The fix in versions 2.32.7, 2.33.8, and 2.34.2 applies the secure transport (TLS 1.2 or higher using system root CAs) unconditionally. As a workaround, 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).

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CVSS v3.1 Score

7.4

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0026

Probability of exploitation

0.17%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-295 CWE-295

Affected Products

Vendor	Product	Versions
coder	coder	2.30.0 — 2.32.7
coder	coder	2.33.0 — 2.33.8
coder	coder	2.34.0 — 2.34.2

References

Advisories & Patches

https://github.com/coder/coder/pull/26131 https://github.com/coder/coder/security/advisories/GHSA-84rm-42xw-mx52

Other References

https://github.com/coder/coder/releases/tag/v2.32.7 https://github.com/coder/coder/releases/tag/v2.33.8 https://github.com/coder/coder/releases/tag/v2.34.2

Frequently Asked Questions

What is CVE-2026-55436? +

Coder allows organizations to provision remote development environments via Terraform. Starting in version 2.30.0 and prior to versions 2.32.7, 2.33.8, and 2.34.2, 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. 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. The fix in versions 2.32.7, 2.33.8, and 2.34.2 applies the secure transport (TLS 1.2 or higher using system root CAs) unconditionally. As a workaround, 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). It has a CVSS v3.1 base score of 7.4 (HIGH).

How severe is CVE-2026-55436? +

CVE-2026-55436 has a CVSS v3.1 score of 7.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-55436? +

CVE-2026-55436 affects products from coder, specifically: coder. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-55436? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-55436