CVE-2026-34839: high-severity vulnerability in nicolargo glances
Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.7epss 0.4%
Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.4, the Glances web server exposes a REST API (`/api/4/*`) that is accessible without authentication and allows cross-origin requests from any origin due to a permissive CORS policy (`Access-Control-Allow-Origin: *`). This allows a malicious website to read sensitive system information from a running Glances instance in the victim’s browser, leading to cross-origin data exfiltration. While a previous advisory exists for XML-RPC CORS issues, this report demonstrates that the REST API (`/api/4/*`) is also affected and exposes significantly more sensitive data. Version 4.5.4 patches the issue.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
Affected products
nicolargo · glancesRelated CVEs — nicolargo glances
In the same product, most dangerous first.
CVE-2026-30928HIGHGlances Exposes Unauthenticated Configuration SecretsEPSS 1.8%CVE-2026-32596HIGHGlances exposes the REST API without authenticationEPSS 1.6%CVE-2026-33641HIGHGlances Vulnerable to Command Injection via Dynamic Configuration ValuesEPSS 0.9%CVE-2026-32609HIGHGlances has Incomplete Secrets Redaction: /api/v4/args Endpoint Leaks Password Hash and SNMP CredentialsEPSS 0.5%CVE-2026-32633CRITICALGlances's Browser API Exposes Reusable Downstream Credentials via `/api/4/serverslist`EPSS 0.5%CVE-2026-68517MEDIUMGlances: REST API CORS Credentials Guard Uses Exact-Match Instead of Membership Test — Bypassed by Any Multi-Origin Allowlist Containing the WildcardEPSS 0.5%