CVE-2026-41518 — Chartbrew has a stored DOM XSS via Chart Tooltip innerHTML (ChartDatasetConfig.legend)
Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. In versions 4.9.0 through 5.0.0, an authenticated user with project-editor permissions can store arbitrary HTML/JavaScript in the `ChartDatasetConfig.legend` field. The payload is persisted verbatim in the database, propagated through the Chart.js rendering pipeline, and injected into the tooltip DOM element via an unguarded `innerHTML` assignment in `ChartTooltip.js`. Every unauthenticated viewer of the public dashboard triggers JavaScript execution on page load — no hover interaction is required. Browser-based Playwright verification confirmed `alert('localhost')` fires immediately and `<img src="x" onerror="alert(document.domain)">` is present in the `#chartjs-tooltip` DOM element. Version 5.0.1 contains a fix.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+4
- Technical severity (high)+6
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Chartbrew Chartbrew).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.6 | CVSS 3.1 | High | 2.3 | 4.7 | security-advisories@github.com via NIST National Vulnerability Database |
| 7.6 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.34%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor CSP violation reports and script payloads in reflected parameters.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · chartbrew/chartbrew
- SSVC assessment updated
- Record published
- CVSS changed · 7.6
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-40904 Chartbrew: Incorrect Access Control in dataset and dataRequest routes via team-scoped permission checks Apr 30, 2026
- High CVE-2026-40601 Chartbrew: Missing Authorization in /api/chart/:chart_id/query via team-level refresh toggle Apr 30, 2026
- Medium CVE-2026-40603 Chartbrew: Incorrect Access Control in /api/project/dashboard/:brewName via same-team override Apr 30, 2026
- High CVE-2026-40595 Chartbrew: Incorrect Access Control in public chart and export routes via missing onReport and SharePolicy checks Apr 30, 2026
- Medium CVE-2026-35514 Unauthenticated Account Registration via /user/invited Bypasses All Signup Restrictions in Chartbrew Apr 30, 2026
- High CVE-2026-40600 Chartbrew: Incorrect Access Control in project share policy routes via unbound policy_id Apr 30, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-41518 is "Chartbrew has a stored DOM XSS via Chart Tooltip innerHTML (ChartDatasetConfig.legend)", rated High. It affects Chartbrew (Chartbrew); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.6 describes technical severity. EPSS 0.34% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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