CVE-2026-48709: CVE-2026-48709: Missing Authorization in OliveTin ValidateArgumentType RPC Endpoint

#security #cve #cybersecurity

CVE-2026-48709: Missing Authorization in OliveTin ValidateArgumentType RPC Endpoint

Vulnerability ID: CVE-2026-48709
CVSS Score: 3.7
Published: 2026-06-24

A missing authorization vulnerability in the OliveTin system allows unauthenticated remote actors to query the ValidateArgumentType RPC endpoint. By exploiting this flaw, attackers can execute systematic brute-force and side-channel validation attacks to enumerate active action binding IDs, parameter structures, and operational metadata, bypassing configured guest authentication barriers.

TL;DR

OliveTin prior to version 3000.13.0 exposes its ValidateArgumentType API endpoint to unauthenticated guest users. Remote attackers can leverage this missing access control to execute oracle-style enumeration attacks, mapping out administrative action binding IDs and parameter requirements.

⚠️ Exploit Status: POC

Technical Details

CWE ID: CWE-862
Attack Vector: Network (AV:N)
CVSS v3.1: 3.7
EPSS Score: 0.00269
Impact: Low (Information Disclosure / Reconnaissance)
Exploit Status: Proof of Concept (PoC) documented
KEV Status: Not listed in CISA KEV

Affected Systems

OliveTin (All versions prior to 3000.13.0)
OliveTin: < 3000.13.0 (Fixed in: 3000.13.0)

Code Analysis

Commit: a386570

Fix unauthorized ValidateArgumentType RPC endpoint validation bypass

@@ -724,12 +724,46 @@ func (api *oliveTinAPI) argumentNotFoundForValidation(msg *apiv1.ValidateArgumen
    return arg == nil
 }

+func (api *oliveTinAPI) validateArgumentTypeBindingAccess(user *authpublic.AuthenticatedUser, msg *apiv1.ValidateArgumentTypeRequest) error {
+... 
+}

Mitigation Strategies

Upgrade OliveTin to version 3000.13.0 or later
Deploy a reverse proxy (Nginx/Caddy) to block access to the ValidateArgumentType RPC endpoints
Use high-entropy, randomized action titles to prevent brute-forcing of binding IDs

Remediation Steps:

Step 1: Identify all running OliveTin containers or binary instances in the environment.
Step 2: Update the deployment configurations (Docker Compose, systemd) to reference version 3000.13.0 or higher.
Step 3: If upgrade is delayed, add a location block in the reverse proxy configuration to return 403 for /api/ValidateArgumentType.
Step 4: Audit existing action titles and rewrite highly predictable names using high-entropy suffixes.

References

Read the full report for CVE-2026-48709 on our website for more details including interactive diagrams and full exploit analysis.

DEV Community