CVE-2026-88062: OmniRoute ACP Custom-Agent Remote Code Execution (RCE)

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.4%, percentile 73: FIRST’s model estimates a 1.4% chance of exploitation activity in the next 30 days, higher than 73% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes omniroute (npm) <= 3.8.50, no fixed version listed. Check your lockfile, including transitive dependencies.

What it is

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 DISALLOWEDVERSIONCOMMANDCHARS 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 LOCALONLYAPIPREFIXES and SPAWNCAPABLEPREFIXES. 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.

From the GitHub advisory

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:

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:

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

When requireLogin=false, isAuthenticated() treats anonymous requests as authenticated. At the same time, /api/acp/ is not included in LOCALONLYAPIPREFIXES or SPAWNCAPABLEPREFIXES, so the endpoint is not blocked by the LOCALONLY 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.

Weakness type: CWE-94, CWE-306.

Product: omniroute (npm) · Assigned by: GitHub_M · Published: 2026-09-10

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.42% probability of exploitation activity in the next 30 days; percentile 73.

Timeline

• 2026-09-10 — CVE record published by GitHub_M
• 2026-09-10 — GitHub-reviewed advisory GHSA-hf57-cqmx-p4gr published (critical)
• 2026-09-11 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-hf57-cqmx-p4gr github.com
2. CVE.org record CVE-2026-88062 cve.org
3. NVD entry CVE-2026-88062 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

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