CVE-2026-26226
beautiful-mermaid < 0.1.3 SVG Attribute Injection
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used 5.3
beautiful-mermaid < 0.1.3 SVG Attribute Injection
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
- Record
CVE-2026-26226- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-08
EUVDEUVD-2026-7382 5.3
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
- Record
EUVD-2026-7382- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Updated
- 2026-11-08
GitHub AdvisoriesGHSA-cgmm-x5ww-q5cr 5.3
beautiful-mermaid contains an SVG attribute injection issue that can lead to cross-site scripting (XSS)
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
- Record
GHSA-cgmm-x5ww-q5cr- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD 5.3
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
- Record
CVE-2026-26226- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV 5.3
beautiful-mermaid < 0.1.3 SVG Attribute Injection
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
- Record
CVE-2026-26226- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-09
OSVGHSA-cgmm-x5ww-q5cr 5.3
beautiful-mermaid contains an SVG attribute injection issue that can lead to cross-site scripting (XSS)
beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.
- Record
GHSA-cgmm-x5ww-q5cr- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
beautiful-mermaidnpm | before 0.1.3 | 0.1.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| references | OSV | |
| references | CVE List | |
| facts | EUVD | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-26226 is a medium vulnerability (CVSS 5.3) in Lukilabs Beautiful-mermaid, published February 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.56%, the 47th percentile. Fixed in beautiful-mermaid 0.1.3.
References
github.com/lukilabs/beautiful-mermaid/releases/tag/v0.1.3
github.com/lukilabs/beautiful-mermaid/pull/8
neo.projectdiscovery.io/share/cec71dc7-a8eb-417e-b8b4-666644796c1e
vulncheck.com/advisories/beautiful-mermaid-svg-attribute-injection
nvd.nist.gov/vuln/detail/CVE-2026-26226
github.com/lukilabs/beautiful-mermaid/commit/68f3ab8c9658e7f4a3b749e06a6b96e4c3f55db1
github.com/advisories/GHSA-cgmm-x5ww-q5cr
github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26226.json
github.com/lukilabs/beautiful-mermaid