CVE-2026-47768: nebula-mesh Newly-minted Operator API Key Exposed Vulnerability

MODERATE
Advisory Identifier: GHSA-9pg3-25fq-p6cc
CVSS 5.5
CWE-116 CWE-532 CWE-598
Published
Advisory Summary

CVE-2026-47768 is a MODERATE (CVSS 5.5) newly-minted operator api key exposed vulnerability (CWE-116: Improper Encoding or Escaping of Output) affecting nebula-mesh libraries in the Go ecosystem. The issue involves newly-minted operator api key exposed in redirect url (referer, history, proxy logs). Remediation is available by upgrading affected packages to version 0.3.2.

CVE-2026-47768 at a Glance

CVE Identifier CVE-2026-47768
GHSA Identifier GHSA-9pg3-25fq-p6cc
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-116: Improper Encoding or Escaping of Output
Affected Product nebula-mesh
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-47768

To remediate this vulnerability, upgrade all affected nebula-mesh dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/juev/nebula-mesh fixed: 0.3.2
Upgrade github.com/juev/nebula-mesh to 0.3.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/juev/nebula-mesh

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-47768, inspect your project dependencies for nebula-mesh:

inspect dependencies for github.com/juev/nebula-mesh

Analyze the terminal output to locate any version of nebula-mesh in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-116: Improper Encoding or Escaping of Output, where the product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. as a result, the intended structure of the message is not preserved. In nebula-mesh, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

`internal/web/operators.go:251` — after `handleOperatorCreateAPIKey` mints a fresh 32-byte bearer token, the redirect points the operator's browser at: /ui/operators/<id>?new_key=<raw-token>&key_name=<name> The raw API key ends up: - in the browser's URL history - in the `Referer` header on every cross-origin asset the detail page loads (any third-party SVG/CSS/JS resource the layout pulls in) - in any reverse-proxy or load-balancer access log on the path (nginx default `combined` log captures the query string) - in any structured log sink the operator's local browser-history backup tool ships out `Authorization: Bearer <token>` headers go through the same hops without these problems because access logs typically don't capture request headers and the browser doesn't replay headers cross-origin. Same handler also appends `name` (`r.FormValue("name")`) to the query string without `url.QueryEscape`, so an `&` in the operator-supplied key name corrupts query parsing and a `\r\n` in older proxies could split response headers. ## Affected All released versions up to v0.3.1. ## Reproducer As admin, create an API key via `/ui/operators/<id>/api-keys` (form POST). The 303 Location header carries the raw token in the query string. Open browser DevTools → Network → response headers; or check the reverse-proxy access log; or check the operator-detail page's `Referer`-emitting fetches. ## Suggested fix Stash the raw key in a one-shot server-side flash storage (e.g., a row in `operator_sessions` keyed by session token, with a `one_shot_token` column and `consumed_at`) or in a short-lived signed cookie. Render the key once inline on the detail page after the redirect, and clear the storage on render. Pattern mirrors the recovery-codes display in the TOTP flow. If the flash-storage refactor is too invasive, the minimal fix is to render the key inline via a `POST` → `200 OK with HTML` (no redirect), losing the post-redirect-get idiom but eliminating the URL exposure. Also fix `name` query encoding with `url.QueryEscape` regardless of which fix shape lands. ## CVSS estimate AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N — 5.5 (medium). AV:L because realistic exploit requires log-read access on shared infrastructure (proxy, CDN, browser-history backup) the operator's session touches.

CVE-2026-47768 Affected nebula-mesh Versions

1 component(s)
Fixed Versions:
0.3.2
Product / Package Ecosystem Affected Versions Fixed Version
github.com/juev/nebula-mesh
Go
< 0.3.2
0.3.2

References

Frequently Asked Questions

What is CVE-2026-47768?
CVE-2026-47768 is a security vulnerability in nebula-mesh involving Newly-minted operator API key exposed in redirect URL (Referer, history, proxy logs) under CWE-116: Improper Encoding or Escaping of Output.
Which nebula-mesh versions are affected?
Affected versions include releases prior to 0.3.2 across affected packages: github.com/juev/nebula-mesh.
What version fixes CVE-2026-47768?
Upgrading to 0.3.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/juev/nebula-mesh affected?
Yes, github.com/juev/nebula-mesh is affected in releases prior to 0.3.2. Upgrade your dependency to 0.3.2 or later.
What is the CVSS score of CVE-2026-47768?
CVE-2026-47768 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-47768?
CVE-2026-47768 is classified under CWE-116: Improper Encoding or Escaping of Output (The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.).
How can I check Go dependencies for CVE-2026-47768?
Run the dependency tree command: 'inspect dependencies for github.com/juev/nebula-mesh'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9pg3-25fq-p6cc",
  "modified" : "2026-06-10T22:13:45Z",
  "published" : "2026-06-10T22:13:45Z",
  "aliases" : [ "CVE-2026-47768" ],
  "summary" : "nebula-mesh: Newly-minted operator API key exposed in redirect URL (Referer, history, proxy logs)",
  "details" : "`internal/web/operators.go:251` — after `handleOperatorCreateAPIKey` mints a fresh 32-byte bearer token, the redirect points the operator's browser at:\n\n    /ui/operators/<id>?new_key=<raw-token>&key_name=<name>\n\nThe raw API key ends up:\n- in the browser's URL history\n- in the `Referer` header on every cross-origin asset the detail page loads (any third-party SVG/CSS/JS resource the layout pulls in)\n- in any reverse-proxy or load-balancer access log on the path (nginx default `combined` log captures the query string)\n- in any structured log sink the operator's local browser-history backup tool ships out\n\n`Authorization: Bearer <token>` headers go through the same hops without these problems because access logs typically don't capture request headers and the browser doesn't replay headers cross-origin.\n\nSame handler also appends `name` (`r.FormValue(\"name\")`) to the query string without `url.QueryEscape`, so an `&` in the operator-supplied key name corrupts query parsing and a `\\r\\n` in older proxies could split response headers.\n\n## Affected\nAll released versions up to v0.3.1.\n\n## Reproducer\nAs admin, create an API key via `/ui/operators/<id>/api-keys` (form POST). The 303 Location header carries the raw token in the query string. Open browser DevTools → Network → response headers; or check the reverse-proxy access log; or check the operator-detail page's `Referer`-emitting fetches.\n\n## Suggested fix\nStash the raw key in a one-shot server-side flash storage (e.g., a row in `operator_sessions` keyed by session token, with a `one_shot_token` column and `consumed_at`) or in a short-lived signed cookie. Render the key once inline on the detail page after the redirect, and clear the storage on render. Pattern mirrors the recovery-codes display in the TOTP flow.\n\nIf the flash-storage refactor is too invasive, the minimal fix is to render the key inline via a `POST` → `200 OK with HTML` (no redirect), losing the post-redirect-get idiom but eliminating the URL exposure.\n\nAlso fix `name` query encoding with `url.QueryEscape` regardless of which fix shape lands.\n\n## CVSS estimate\nAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N — 5.5 (medium). AV:L because realistic exploit requires log-read access on shared infrastructure (proxy, CDN, browser-history backup) the operator's session touches.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/juev/nebula-mesh"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.3.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/juev/nebula-mesh/security/advisories/GHSA-9pg3-25fq-p6cc"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/juev/nebula-mesh"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-116", "CWE-532", "CWE-598" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-10T22:13:45Z",
    "nvd_published_at" : null
  }
}