CVE-2026-71436
Mermaid XY Charts are vulnerable to an infinite loop DoS
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
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
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.3
Mermaid XY Charts are vulnerable to an infinite loop DoS
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
- Record
CVE-2026-71436- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L - Weakness
- CWE-835, CWE-1325
- Updated
- 2026-11-02
EUVDEUVD-2026-54241
5.3
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
- Record
EUVD-2026-54241- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2v8p-3f2j-5mp7
5.3
Mermaid XY Charts are vulnerable to an infinite loop DoS
Impact
Mermaid XY Charts are vulnerable to an infinite loop DoS attack in the setXAxisRangeData(), when configuring an X-Axis with invalid parameters.
As each loop appends an element to an array, this would generally only cause an RangeError: Invalid array length to appear after a few seconds, but may cause the page/JavaScript process to crash due to memory exhaustion, depending on the environment.
Proof-of-concept
xychart
x-axis 1 --> 1
line [1, 2]
Patches
This has been patched in https://github.com/mermaid-js/mermaid/commit/630aa7e5dd417e1f56bff2a1ce8df2c5ad08d289 and released in Mermaid v11.16.1.
A backport has been made for the v10 branch in ef60adc837d9d5107af21285f01e83dea309bd0a and was released in Mermaid v10.9.8
Workarounds
There are no known workarounds. Please update to the latest version or apply the patch.
References
- Record
GHSA-2v8p-3f2j-5mp7- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L - Weakness
- CWE-835, CWE-1325
- Updated
- 2026-11-02
NVD
5.3
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
- Record
CVE-2026-71436- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/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-835, CWE-1325
- Updated
- 2026-11-02
OSV
5.3
Mermaid XY Charts are vulnerable to an infinite loop DoS
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
- Record
CVE-2026-71436- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L - Weakness
- CWE-1325, CWE-835
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-71436
5.3
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
- Record
DEBIAN-CVE-2026-71436- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/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 - Updated
- 2026-11-02
OSVGHSA-2v8p-3f2j-5mp7
5.3
Mermaid XY Charts are vulnerable to an infinite loop DoS
Impact
Mermaid XY Charts are vulnerable to an infinite loop DoS attack in the setXAxisRangeData(), when configuring an X-Axis with invalid parameters.
As each loop appends an element to an array, this would generally only cause an RangeError: Invalid array length to appear after a few seconds, but may cause the page/JavaScript process to crash due to memory exhaustion, depending on the environment.
Proof-of-concept
xychart
x-axis 1 --> 1
line [1, 2]
Patches
This has been patched in https://github.com/mermaid-js/mermaid/commit/630aa7e5dd417e1f56bff2a1ce8df2c5ad08d289 and released in Mermaid v11.16.1.
A backport has been made for the v10 branch in ef60adc837d9d5107af21285f01e83dea309bd0a and was released in Mermaid v10.9.8
Workarounds
There are no known workarounds. Please update to the latest version or apply the patch.
References
- Record
GHSA-2v8p-3f2j-5mp7- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L - Weakness
- CWE-1325, CWE-835
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-71436
5.3
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
- Record
UBUNTU-CVE-2026-71436- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mermaidnpm |
10.6.0 up to 10.9.8 | 10.9.8 |
mermaidnpm |
11.0.0-alpha.1 up to 11.16.1 | 11.16.1 |
node-mermaidDebian:14 |
All versions, plus listed versions 8.11.0+ds+~cs29.13.22-18.13.2+ds+~cs30.13.21-18.13.2+ds+~cs30.13.21-1.18.13.3+ds+~cs26.13.21-18.13.3+ds+~cs26.13.21-2 Show 11 moreShow less8.13.8+~cs10.4.16-18.14.0+ds1+~cs11.4.14-18.14.0+~cs11.4.14-18.7.0+ds+~cs27.17.17-18.7.0+ds+~cs27.17.17-28.7.0+ds+~cs27.17.17-2~bpo10+18.7.0+ds+~cs27.17.17-38.9.1+ds+~cs26.20.25-18.9.3+ds+~cs29.13.19-19.2.2+~2.0.0-19.2.2+~2.0.0-2 |
None known |
node-mermaidUbuntu:22.04:LTS |
All versions, plus listed versions 8.7.0+ds+~cs27.17.17-38.13.3+ds+~cs26.13.21-18.13.3+ds+~cs26.13.21-28.13.8+~cs10.4.16-1 |
None known |
node-mermaidUbuntu:26.10 |
All versions, plus listed versions 9.2.2+~2.0.0-19.2.2+~2.0.0-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-71436 is a medium vulnerability (CVSS 5.3) in Mermaid-js Mermaid, published August 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.58%, the 47th percentile. Fixed in mermaid 10.9.8.
References
github.com/mermaid-js/mermaid/security/advisories/GHSA-2v8p-3f2j-5mp7
github.com/mermaid-js/mermaid/pull/8022
github.com/mermaid-js/mermaid/commit/630aa7e5dd417e1f56bff2a1ce8df2c5ad08d289
github.com/mermaid-js/mermaid/commit/ef60adc837d9d5107af21285f01e83dea309bd0a
github.com/mermaid-js/mermaid/releases/tag/[email protected]
github.com/mermaid-js/mermaid/releases/tag/v10.9.8
Show 7 moreShow less
github.com/advisories/GHSA-2v8p-3f2j-5mp7
github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71436.json
nvd.nist.gov/vuln/detail/CVE-2026-71436
security-tracker.debian.org/tracker/CVE-2026-71436
github.com/mermaid-js/mermaid
ubuntu.com/security/CVE-2026-71436
cve.org/CVERecord?id=CVE-2026-71436