CVE-2026-44479

Description

Vercel’s AI Cloud is a unified platform for building modern applications. From 50.16.0 to 52.0.0, hen the Vercel CLI runs in non-interactive mode (--non-interactive or auto-detected AI agent), commands that cannot complete autonomously emit JSON payloads with suggested follow-up commands. If the user authenticated via --token or -t on the command line, the token value is included verbatim in those suggestions. The plaintext token may be captured in CI/CD logs, agent transcripts, or other automation output. This vulnerability is fixed in 52.0.1.

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Configurations (Affected Products)

No configuration data available.

Vercel CLI >= 50.16.0, <= 52.0.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# Simulated PoC demonstrating the vulnerability behavior
import json
import sys

def simulate_vulnerable_cli(command, token):
    print(f"[Simulated CLI] Executing: {command} with token {token[:4]}****")
    
    # Simulating a scenario where interaction is needed in non-interactive mode
    needs_interaction = True
    
    if needs_interaction:
        response_payload = {
            "status": "needs_action",
            "message": "Confirmation required",
            "suggested_command": f"{command} --token {token} --confirm"
        }
        # Outputting JSON with sensitive token
        print(json.dumps(response_payload, indent=2))

if __name__ == "__main__":
    # Example usage representing the leak
    simulate_vulnerable_cli("vercel deploy", "vcl_1234567890abcdef_secret_token_value")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44479
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44479
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44479/
[4] VulDB https://vuldb.com/cve/CVE-2026-44479
[5] https://github.com/vercel/vercel/security/advisories/GHSA-pgf8-2hgj-grqg

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44479", "sourceIdentifier": "[email protected]", "published": "2026-05-13T16:16:58.400", "lastModified": "2026-05-13T16:58:40.557", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Vercel’s AI Cloud is a unified platform for building modern applications. From 50.16.0 to 52.0.0, hen the Vercel CLI runs in non-interactive mode (--non-interactive or auto-detected AI agent), commands that cannot complete autonomously emit JSON payloads with suggested follow-up commands. If the user authenticated via --token or -t on the command line, the token value is included verbatim in those suggestions. The plaintext token may be captured in CI/CD logs, agent transcripts, or other automation output. This vulnerability is fixed in 52.0.1."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-532"}]}], "references": [{"url": "https://github.com/vercel/vercel/security/advisories/GHSA-pgf8-2hgj-grqg", "source": "[email protected]"}]}}