CVE-2026-61793

Nuxt OG Image generates OG Images with Vue templates in Nuxt. From 6.0.2 until 6.7.0, nuxt-og-image exposes the unauthenticated /_og/d/** route when the documented defaults security.strict = false and security.secret = "" are used, and base64url-decodes the fonts parameter through decodeOgImageParams. Attacker-controlled fonts[].path values flow through loadDefinedFonts into the font-assets/node.js binding, which performs a server-side fetch without validating the URL scheme, origin, resolved address, or redirects. This permits blind requests to loopback, private, link-local, cloud metadata, and other internal HTTP services, while differences in the outer response status and timing can reveal service reachability. Slow targets can also occupy OG image render workers for the configured fetch and render timeouts. This issue is fixed in version 6.7.0.

Nuxt OG Image generates OG Images with Vue templates in Nuxt. From 6.0.2 until 6.7.0, nuxt-og-image exposes the unauthenticated /_og/d/** route when the documented defaults security.strict = false and security.secret = "" are used, and base64url-decodes the fonts parameter through decodeOgImageParams. Attacker-controlled fonts[].path values flow through loadDefinedFonts into the font-assets/node.js binding, which performs a server-side fetch without validating the URL scheme, origin, resolved address, or redirects. This permits blind requests to loopback, private, link-local, cloud metadata, and other internal HTTP services, while differences in the outer response status and timing can reveal service reachability. Slow targets can also occupy OG image render workers for the configured fetch and render timeouts. This issue is fixed in version 6.7.0.

Summary

nuxt-og-image exposes an unauthenticated HTTP endpoint at /_og/d/** that base64url-decodes and JSON.parses a fonts URL segment, then passes each fonts[i].path value directly into fetch() server-side without any URL validation (no scheme allowlist, no loopback/RFC1918 block, no host allowlist, no DNS rebinding mitigation).

Under the module's documented default configuration (security.strict = false, security.secret = "", restrictRuntimeImagesToOrigin = false), any caller able to reach the deployed Nuxt site can force the Nuxt server to issue arbitrary outbound GET requests to any host reachable from the server - including loopback, RFC1918 LAN, and cloud metadata services (AWS IMDS, GCE/Azure metadata, Kubernetes kubelet, internal admin panels, Redis/etcd/Consul/Vault HTTP APIs).

The chain is blind (Satori consumes the response as font bytes and silently discards non-fonts) but a robust side-channel exists: the outer HTTP status is 500 when the SSRF target returns 2xx, and 200 when it fails or returns non-2xx. This is sufficient to (a) enumerate live internal services and open ports, (b) confirm IMDSv1 reachability, and (c) detect credential issuance on environments still allowing IMDSv1.

Demonstrated end-to-end on a stock npm create nuxt@latest install with the module's documented default usage.

Detail

Endpoint registration (unauthenticated)

The module registers /_og/d/** and /_og/s/** with no authentication / Origin check / Sec‑Fetch‑Site validation:

// dist/shared/nuxt-og-image.DdbTs-xp.mjs : 5113-5133
addServerHandler({ route: "/_og/d/**", handler: resolve("./runtime/server/routes/image") })
addServerHandler({ route: "/_og/s/**", handler: resolve("./runtime/server/routes/image") })

Default security config (permissive)

// dist/shared/nuxt-og-image.DdbTs-xp.mjs : 5618-5640
security: {
  strict:                       config.security?.strict ?? false,         // <- gate disabled
  secret:                       config.security?.secret ?? process.env.NUXT_OG_IMAGE_SECRET ?? "",
                                                                          //   ↑ no signature requirement
  restrictRuntimeImagesToOrigin: config.security?.restrictRuntimeImagesToOrigin ?? false,
                                                                          //   ↑ inbound host allowlist disabled
  maxQueryParamSize:            config.security?.maxQueryParamSize ?? null,
  renderTimeout:                config.security?.renderTimeout ?? 15000,
  imageFetchTimeout:            config.security?.imageFetchTimeout ?? 3000,
}

The secret/signature branch is gated on secret && (truthy), so an empty string skips it entirely:

// dist/runtime/server/og-image/context.js : 49-69
const secret = runtimeConfig.security?.secret
let paramsSegment = encodedSegment
if (secret && !import.meta.dev && !import.meta.prerender) {
  // signature enforcement happens HERE - but only if secret is non-empty.
  // Default install: secret === "" -> entire block skipped.
}

Attacker-controlled deserialization of fonts

fonts is enumerated as a complex parameter: its value is base64url-decoded and then JSON.parsed straight into options:

// dist/runtime/shared/urlEncoding.js : 65
const COMPLEX_PARAMS = new Set(["satori","resvg","sharp","screenshot","takumi","fonts","_query","_path"])

// dist/runtime/shared/urlEncoding.js : 184-231
export function decodeOgImageParams(encoded) {
  ...
  for (const part of parts) {
    const idx = part.search(RE_SINGLE_UNDERSCORE)
    if (idx === -1) continue
    const alias = part.slice(0, idx)
    let value = part.slice(idx + 1)
    const paramName = PARAM_ALIASES[alias] || alias
    if (COMPLEX_PARAMS.has(paramName)) {
      try {
        const json = b64Decode(value)
        options[paramName] = JSON.parse(json)        // <- attacker JSON survives unchanged
      } catch { options[paramName] =…

Nuxt OG Image generates OG Images with Vue templates in Nuxt. From 6.0.2 until 6.7.0, nuxt-og-image exposes the unauthenticated /_og/d/** route when the documented defaults security.strict = false and security.secret = "" are used, and base64url-decodes the fonts parameter through decodeOgImageParams. Attacker-controlled fonts[].path values flow through loadDefinedFonts into the font-assets/node.js binding, which performs a server-side fetch without validating the URL scheme, origin, resolved address, or redirects. This permits blind requests to loopback, private, link-local, cloud metadata, and other internal HTTP services, while differences in the outer response status and timing can reveal service reachability. Slow targets can also occupy OG image render workers for the configured fetch and render timeouts. This issue is fixed in version 6.7.0.

Nuxt OG Image generates OG Images with Vue templates in Nuxt. From 6.0.2 until 6.7.0, nuxt-og-image exposes the unauthenticated /_og/d/** route when the documented defaults security.strict = false and security.secret = "" are used, and base64url-decodes the fonts parameter through decodeOgImageParams. Attacker-controlled fonts[].path values flow through loadDefinedFonts into the font-assets/node.js binding, which performs a server-side fetch without validating the URL scheme, origin, resolved address, or redirects. This permits blind requests to loopback, private, link-local, cloud metadata, and other internal HTTP services, while differences in the outer response status and timing can reveal service reachability. Slow targets can also occupy OG image render workers for the configured fetch and render timeouts. This issue is fixed in version 6.7.0.

Summary

nuxt-og-image exposes an unauthenticated HTTP endpoint at /_og/d/** that base64url-decodes and JSON.parses a fonts URL segment, then passes each fonts[i].path value directly into fetch() server-side without any URL validation (no scheme allowlist, no loopback/RFC1918 block, no host allowlist, no DNS rebinding mitigation).

Under the module's documented default configuration (security.strict = false, security.secret = "", restrictRuntimeImagesToOrigin = false), any caller able to reach the deployed Nuxt site can force the Nuxt server to issue arbitrary outbound GET requests to any host reachable from the server - including loopback, RFC1918 LAN, and cloud metadata services (AWS IMDS, GCE/Azure metadata, Kubernetes kubelet, internal admin panels, Redis/etcd/Consul/Vault HTTP APIs).

The chain is blind (Satori consumes the response as font bytes and silently discards non-fonts) but a robust side-channel exists: the outer HTTP status is 500 when the SSRF target returns 2xx, and 200 when it fails or returns non-2xx. This is sufficient to (a) enumerate live internal services and open ports, (b) confirm IMDSv1 reachability, and (c) detect credential issuance on environments still allowing IMDSv1.

Demonstrated end-to-end on a stock npm create nuxt@latest install with the module's documented default usage.

Detail

Endpoint registration (unauthenticated)

The module registers /_og/d/** and /_og/s/** with no authentication / Origin check / Sec‑Fetch‑Site validation:

// dist/shared/nuxt-og-image.DdbTs-xp.mjs : 5113-5133
addServerHandler({ route: "/_og/d/**", handler: resolve("./runtime/server/routes/image") })
addServerHandler({ route: "/_og/s/**", handler: resolve("./runtime/server/routes/image") })

Default security config (permissive)

// dist/shared/nuxt-og-image.DdbTs-xp.mjs : 5618-5640
security: {
  strict:                       config.security?.strict ?? false,         // <- gate disabled
  secret:                       config.security?.secret ?? process.env.NUXT_OG_IMAGE_SECRET ?? "",
                                                                          //   ↑ no signature requirement
  restrictRuntimeImagesToOrigin: config.security?.restrictRuntimeImagesToOrigin ?? false,
                                                                          //   ↑ inbound host allowlist disabled
  maxQueryParamSize:            config.security?.maxQueryParamSize ?? null,
  renderTimeout:                config.security?.renderTimeout ?? 15000,
  imageFetchTimeout:            config.security?.imageFetchTimeout ?? 3000,
}

The secret/signature branch is gated on secret && (truthy), so an empty string skips it entirely:

// dist/runtime/server/og-image/context.js : 49-69
const secret = runtimeConfig.security?.secret
let paramsSegment = encodedSegment
if (secret && !import.meta.dev && !import.meta.prerender) {
  // signature enforcement happens HERE - but only if secret is non-empty.
  // Default install: secret === "" -> entire block skipped.
}

Attacker-controlled deserialization of fonts

fonts is enumerated as a complex parameter: its value is base64url-decoded and then JSON.parsed straight into options:

// dist/runtime/shared/urlEncoding.js : 65
const COMPLEX_PARAMS = new Set(["satori","resvg","sharp","screenshot","takumi","fonts","_query","_path"])

// dist/runtime/shared/urlEncoding.js : 184-231
export function decodeOgImageParams(encoded) {
  ...
  for (const part of parts) {
    const idx = part.search(RE_SINGLE_UNDERSCORE)
    if (idx === -1) continue
    const alias = part.slice(0, idx)
    let value = part.slice(idx + 1)
    const paramName = PARAM_ALIASES[alias] || alias
    if (COMPLEX_PARAMS.has(paramName)) {
      try {
        const json = b64Decode(value)
        options[paramName] = JSON.parse(json)        // <- attacker JSON survives unchanged
      } catch { options[paramName] =…