CVE-2026-88062

OmniRoute is an open-source AI gateway providing a single endpoint for multiple model providers. In 3.8.49 and earlier, the OmniRoute POST /api/acp/agents custom ACP agent endpoint accepted attacker-controlled binary and versionCommand values and used only a self-consistency check before execFileSync executed the selected interpreter and arguments. The same request called refreshAgentCache, and resolveVersionProbe accepted the matched command before the execFileSync sink ran it. The tokenizeVersionCommand function and DISALLOWED_VERSION_COMMAND_CHARS filter rejected a limited set of shell metacharacters but still allowed interpreter evaluation arguments. The isAuthenticated function relied on isAuthRequired, which accepted anonymous requests when requireLogin was false, while api/acp/ was absent from LOCAL_ONLY_API_PREFIXES and SPAWN_CAPABLE_PREFIXES. With requireLogin=false or during a fresh-instance bootstrap window, a remote anonymous request could supply an interpreter evaluation argument and execute arbitrary code in the server container. With requireLogin=true and a configured management password, exploitation instead required a management session or management-scoped API key. No fixed version is available as of this review.

OmniRoute is an open-source AI gateway providing a single endpoint for multiple model providers. In 3.8.49 and earlier, the OmniRoute POST /api/acp/agents custom ACP agent endpoint accepted attacker-controlled binary and versionCommand values and used only a self-consistency check before execFileSync executed the selected interpreter and arguments. The same request called refreshAgentCache, and resolveVersionProbe accepted the matched command before the execFileSync sink ran it. The tokenizeVersionCommand function and DISALLOWED_VERSION_COMMAND_CHARS filter rejected a limited set of shell metacharacters but still allowed interpreter evaluation arguments. The isAuthenticated function relied on isAuthRequired, which accepted anonymous requests when requireLogin was false, while api/acp/ was absent from LOCAL_ONLY_API_PREFIXES and SPAWN_CAPABLE_PREFIXES. With requireLogin=false or during a fresh-instance bootstrap window, a remote anonymous request could supply an interpreter evaluation argument and execute arbitrary code in the server container. With requireLogin=true and a configured management password, exploitation instead required a management session or management-scoped API key. No fixed version is available as of this review.

2. Summary

POST /api/acp/agents registers a custom ACP agent. The endpoint accepts user-controlled binary and versionCommand values. After saving the custom agent, the same request calls refreshAgentCache(), which triggers agent version detection. The version probe eventually runs:

execFileSync(probe.command, probe.args, ...)

The only validation is resolveVersionProbe(binary, versionCommand, true), which checks that the first token of versionCommand matches the request-provided binary. Because binary is also attacker-controlled, an attacker can submit:

{
  "binary": "node",
  "versionCommand": "node -e \"...arbitrary JavaScript...\""
}

This executes arbitrary Node.js code inside the server container, and that code can execute OS commands via child_process.execSync().

When requireLogin=false, isAuthenticated() treats anonymous requests as authenticated. At the same time, /api/acp/ is not included in LOCAL_ONLY_API_PREFIXES or SPAWN_CAPABLE_PREFIXES, so the endpoint is not blocked by the LOCAL_ONLY policy before reaching the anonymous allow branch. As a result, a remote anonymous attacker can execute commands inside the OmniRoute container with a single HTTP request.

3. Preconditions

The unauthenticated exploit is reachable in either of the following scenarios:

1. The target instance has requireLogin=false. This is the primary scenario covered by this report and by the reproduction steps below.
2. A fresh instance has no management password configured yet. During this bootstrap window, /api/settings/require-login allows unauthenticated setup writes, so an attacker can first set requireLogin=false and then call the vulnerable endpoint.

If the instance is in the default requireLogin=true state and already has a management password, exploitation requires a valid management session or management-scoped API key. In that case, the bug is authenticated RCE rather than the unauthenticated scenario emphasized here.

4. Technical Analysis

4.1 The Endpoint Accepts User-Controlled Command Fields

src/app/api/acp/agents/route.ts:15-24 defines a request schema that accepts binary, versionCommand, and spawnArgs:

const customAgentBodySchema = z.object({
  action: z.string().optional(),
  id: z.string().optional(),
  name: z.string().optional(),
  binary: z.string().optional(),
  versionCommand: z.string().optional(),
  providerAlias: z.string().optional(),
  spawnArgs: z.array(z.string()).optional(),
  protocol: z.enum(["stdio", "http"]).optional(),
});

The POST handler at src/app/api/acp/agents/route.ts:58-61 only calls isAuthenticated():

export async function POST(request: Request) {
  if (!(await isAuthenticated(request))) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

The handler then stores binary and versionCommand in the custom agent definition without an executable allowlist:

const newAgent: CustomAgentDef = {
  id: id.toLowerCase().replace(/[^a-z0-9-]/g, "-"),
  name,
  binary,
  versionCommand,
  providerAlias: providerAlias || id,
  spawnArgs: spawnArgs || [],
  protocol: protocol || "stdio",
};

This logic is in src/app/api/acp/agents/route.ts:92-100.

4.2 The Only Guard Is a Self-Consistency Check

The only command validation in the route is at src/app/api/acp/agents/route.ts:102-107:

if (!resolveVersionProbe(newAgent.binary, newAgent.versionCommand, true)) {
  return NextResponse.json(
    { error: "Invalid versionCommand: use the configured binary with plain arguments only" },
    { status: 400 }
  );
}

The core logic of resolveVersionProbe() is in src/lib/acp/registry.ts:261-288:

export function resolveVersionProbe(
  binary: string,
  versionCommand: string,
  requireBinaryMatch = false
): { command: string; args: string[] } | null {
  const tokens = tokenizeVersionCommand(versionCommand);
  if (!tokens) {
    return null;…

OmniRoute is an open-source AI gateway providing a single endpoint for multiple model providers. In 3.8.49 and earlier, the OmniRoute POST /api/acp/agents custom ACP agent endpoint accepted attacker-controlled binary and versionCommand values and used only a self-consistency check before execFileSync executed the selected interpreter and arguments. The same request called refreshAgentCache, and resolveVersionProbe accepted the matched command before the execFileSync sink ran it. The tokenizeVersionCommand function and DISALLOWED_VERSION_COMMAND_CHARS filter rejected a limited set of shell metacharacters but still allowed interpreter evaluation arguments. The isAuthenticated function relied on isAuthRequired, which accepted anonymous requests when requireLogin was false, while api/acp/ was absent from LOCAL_ONLY_API_PREFIXES and SPAWN_CAPABLE_PREFIXES. With requireLogin=false or during a fresh-instance bootstrap window, a remote anonymous request could supply an interpreter evaluation argument and execute arbitrary code in the server container. With requireLogin=true and a configured management password, exploitation instead required a management session or management-scoped API key. No fixed version is available as of this review.

OmniRoute is an open-source AI gateway providing a single endpoint for multiple model providers. In 3.8.49 and earlier, the OmniRoute POST /api/acp/agents custom ACP agent endpoint accepted attacker-controlled binary and versionCommand values and used only a self-consistency check before execFileSync executed the selected interpreter and arguments. The same request called refreshAgentCache, and resolveVersionProbe accepted the matched command before the execFileSync sink ran it. The tokenizeVersionCommand function and DISALLOWED_VERSION_COMMAND_CHARS filter rejected a limited set of shell metacharacters but still allowed interpreter evaluation arguments. The isAuthenticated function relied on isAuthRequired, which accepted anonymous requests when requireLogin was false, while api/acp/ was absent from LOCAL_ONLY_API_PREFIXES and SPAWN_CAPABLE_PREFIXES. With requireLogin=false or during a fresh-instance bootstrap window, a remote anonymous request could supply an interpreter evaluation argument and execute arbitrary code in the server container. With requireLogin=true and a configured management password, exploitation instead required a management session or management-scoped API key. No fixed version is available as of this review.

2. Summary

POST /api/acp/agents registers a custom ACP agent. The endpoint accepts user-controlled binary and versionCommand values. After saving the custom agent, the same request calls refreshAgentCache(), which triggers agent version detection. The version probe eventually runs:

execFileSync(probe.command, probe.args, ...)

The only validation is resolveVersionProbe(binary, versionCommand, true), which checks that the first token of versionCommand matches the request-provided binary. Because binary is also attacker-controlled, an attacker can submit:

{
  "binary": "node",
  "versionCommand": "node -e \"...arbitrary JavaScript...\""
}

This executes arbitrary Node.js code inside the server container, and that code can execute OS commands via child_process.execSync().

When requireLogin=false, isAuthenticated() treats anonymous requests as authenticated. At the same time, /api/acp/ is not included in LOCAL_ONLY_API_PREFIXES or SPAWN_CAPABLE_PREFIXES, so the endpoint is not blocked by the LOCAL_ONLY policy before reaching the anonymous allow branch. As a result, a remote anonymous attacker can execute commands inside the OmniRoute container with a single HTTP request.

3. Preconditions

The unauthenticated exploit is reachable in either of the following scenarios:

1. The target instance has requireLogin=false. This is the primary scenario covered by this report and by the reproduction steps below.
2. A fresh instance has no management password configured yet. During this bootstrap window, /api/settings/require-login allows unauthenticated setup writes, so an attacker can first set requireLogin=false and then call the vulnerable endpoint.

If the instance is in the default requireLogin=true state and already has a management password, exploitation requires a valid management session or management-scoped API key. In that case, the bug is authenticated RCE rather than the unauthenticated scenario emphasized here.

4. Technical Analysis

4.1 The Endpoint Accepts User-Controlled Command Fields

src/app/api/acp/agents/route.ts:15-24 defines a request schema that accepts binary, versionCommand, and spawnArgs:

const customAgentBodySchema = z.object({
  action: z.string().optional(),
  id: z.string().optional(),
  name: z.string().optional(),
  binary: z.string().optional(),
  versionCommand: z.string().optional(),
  providerAlias: z.string().optional(),
  spawnArgs: z.array(z.string()).optional(),
  protocol: z.enum(["stdio", "http"]).optional(),
});

The POST handler at src/app/api/acp/agents/route.ts:58-61 only calls isAuthenticated():

export async function POST(request: Request) {
  if (!(await isAuthenticated(request))) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

The handler then stores binary and versionCommand in the custom agent definition without an executable allowlist:

const newAgent: CustomAgentDef = {
  id: id.toLowerCase().replace(/[^a-z0-9-]/g, "-"),
  name,
  binary,
  versionCommand,
  providerAlias: providerAlias || id,
  spawnArgs: spawnArgs || [],
  protocol: protocol || "stdio",
};

This logic is in src/app/api/acp/agents/route.ts:92-100.

4.2 The Only Guard Is a Self-Consistency Check

The only command validation in the route is at src/app/api/acp/agents/route.ts:102-107:

if (!resolveVersionProbe(newAgent.binary, newAgent.versionCommand, true)) {
  return NextResponse.json(
    { error: "Invalid versionCommand: use the configured binary with plain arguments only" },
    { status: 400 }
  );
}

The core logic of resolveVersionProbe() is in src/lib/acp/registry.ts:261-288:

export function resolveVersionProbe(
  binary: string,
  versionCommand: string,
  requireBinaryMatch = false
): { command: string; args: string[] } | null {
  const tokens = tokenizeVersionCommand(versionCommand);
  if (!tokens) {
    return null;…