Information Disclosure in glances (CVE-2026-34839)
Summary
Vulnerability in glances (CVE-2026-34839). Confidential information can be exposed externally. Exploitable via processlist. Mitigation: upgrade to 4.5.4 or later.
Original description
The description as published by the source.
Summary
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.
Details
When Glances is started in web mode (e.g., glances -w -B 0.0.0.0), it exposes a REST API endpoint at:
http://:61208/api/4/all
The server responds with:
Access-Control-Allow-Origin: *
This allows any origin to perform cross-origin requests and read responses.
The /api/4/all endpoint returns extensive system information, including:
- Process list (
processlist) - System details (hostname, OS, CPU info)
- Memory and disk usage
- Network interfaces and IP address
- Running services and metrics
Because no authentication is required by default, this data is accessible to any web page.
PoC
-
Start Glances:
glances -w -B 0.0.0.0 -
Create a malicious HTML file:
<!DOCTYPE html>
fetch("http://:61208/api/4/all")
.then(r => r.json())
.then(data => {
console.log("DATA:", data);
});
- Open the file in a browser while Glances is running.
- Observe that the browser successfully…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-34839 has been found in glances.
Attackers can target a specific entry point like processlist over the network to misuse the product.
Confidential information can be exposed externally.
What to do: upgrade glances to 4.5.4 or later.
If unsure, ask your IT team or search "glances CVE-2026-34839" on the vendor's site.
CVE-2026-34839 (glances) — CWE-200
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: processlist
Patched: 4.5.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) exists in glances. Attackers reach the vulnerable code path via processlist without authentication.
Check the vendor advisory for the affected versions of glances. Attack surface: processlist.
Severity: ?. Confidential information can be exposed externally.
Update to 4.5.4.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'glances' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'glances' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
glancesを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade glances to 4.5.4ステージング環境で 4.5.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-34839 glances
- Ubuntu UBUNTU-CVE-2026-34839 glances
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com