CVE-2026-55436: Github.com/coder/coder/v2 Coder's AI Bridge Proxy Skips Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-84rm-42xw-mx52",
  "modified" : "2026-07-06T21:12:05Z",
  "published" : "2026-07-06T21:12:05Z",
  "aliases" : [ "CVE-2026-55436" ],
  "summary" : "Coder's AI Bridge Proxy skips TLS certificate verification in default configuration",
  "details" : "### Summary\n\nThe 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.\n\n> **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.\n\n### Impact\n\nAn 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.\n\n### Patches\n\nThe 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.\n\nThe fix is available in the following releases:\n\n| Release line | Patched version |\n|---|---|\n| 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) |\n| 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) |\n| 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) |\n\n### Workarounds\n\nEnsure 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).\n\n### Resources\n\n- Fix: #26131\n\n### Credits\n\nCoder would like to thank Anthropic's Security Team (ANT-2026-22455) for independently disclosing this issue!",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.34.0"
      }, {
        "fixed" : "2.34.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.33.0"
      }, {
        "fixed" : "2.33.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/coder/coder/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.30.0"
      }, {
        "fixed" : "2.32.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/security/advisories/GHSA-84rm-42xw-mx52"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/coder/coder/pull/26131"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/coder/coder"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-295" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-06T21:12:05Z",
    "nvd_published_at" : null
  }
}