Vulnerability in prometheus (UBUNTU-CVE-2026-44903)

Summary

Vulnerability in prometheus (UBUNTU-CVE-2026-44903). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 3.5.3 or later.

Original description

The description as published by the source.

Prometheus is an open-source monitoring system and time series database. From 2.49.0 to before 3.5.3 and 3.11.3, in the Prometheus server's legacy web UI (enabled via the command-line flag --enable-feature=old-ui), the histogram heatmap chart view does not escape le label values when inserting them into the HTML for use as axis tick mark labels. An attacker who can inject crafted metrics can execute JavaScript in the browser of any Prometheus user who views the metric in the heatmap chart UI. This vulnerability is fixed in 3.5.3 and 3.11.3.

Source: OSV.dev (Open Source Vulnerabilities) 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 UBUNTU-CVE-2026-44903 has been found in prometheus.
Risk of unauthorized operations or information disclosure.
What to do: upgrade prometheus to 3.5.3 or later.
If unsure, ask your IT team or search "prometheus UBUNTU-CVE-2026-44903" on the vendor's site.

UBUNTU-CVE-2026-44903 (prometheus)
Attack vector: remote (network-reachable) / unauthenticated
Patched: 3.5.3 — 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.

❓ What is the problem

A vulnerability (unclassified) exists in prometheus.

📍 Affected scope

Check the vendor advisory for the affected versions of prometheus.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 3.5.3.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'prometheus' . 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

1
Identify exposure identify
```
grep -r 'prometheus' . | 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 prometheus を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade prometheus to 3.5.3
```
ステージング環境で 3.5.3 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。
3
Post-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。