CVE-2026-66921: Pivotick’s Markdown node-reference renderer failed to HTML-escape the attacker-controlled nodeName value before interpolating it into both the data-no...

Description

Pivotick’s Markdown node-reference renderer failed to HTML-escape the attacker-controlled nodeName value before interpolating it into both the data-node-name attribute and the body of a generated <span> element. Because the node-reference tokenizer rejected only square brackets, a crafted node name could still contain quotation marks, angle brackets, or other HTML metacharacters. An attacker could therefore terminate the quoted attribute or inject additional HTML elements and event-handler attributes. When malicious node-reference content is rendered by a consumer that does not apply DOMPurify or equivalent sanitization, arbitrary JavaScript may execute in the victim’s browser in the security context of the application. Successful exploitation requires a victim to open or render a crafted graph or note and could allow the attacker to access same-origin information, modify displayed content, or perform actions using the victim’s session. The patch resolves the issue by applying context-appropriate HTML escaping to node names before inserting them into either HTML text or quoted attribute values. The shared escaping function now encodes ampersands, angle brackets, and both types of quotation marks.

Metrics

CVSS 4.0

6.3/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:H/SA:H/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

EPSS Probability

0.28%

19.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
pivotick	pivotick	<= 1.4.0

References

https://github.com/Pivotick/Pivotick/commit/4c13ff2b0ec769881b5526feddef37c0c5a08885

Timeline

Published: Jul 28, 2026
Last Modified: Jul 30, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-66921?

Pivotick’s Markdown node-reference renderer failed to HTML-escape the attacker-controlled nodeName value before interpolating it into both the data-node-name attribute and the body of a generated <span> element. Because the node-reference tokenizer rejected only square brackets, a crafted node name could still contain quotation marks, angle brackets, or other HTML metacharacters. An attacker could therefore terminate the quoted attribute or inject additional HTML elements and event-handler attributes. When malicious node-reference content is rendered by a consumer that does not apply DOMPurify or equivalent sanitization, arbitrary JavaScript may execute in the victim’s browser in the security context of the application. Successful exploitation requires a victim to open or render a crafted graph or note and could allow the attacker to access same-origin information, modify displayed content, or perform actions using the victim’s session. The patch resolves the issue by applying context-appropriate HTML escaping to node names before inserting them into either HTML text or quoted attribute values. The shared escaping function now encodes ampersands, angle brackets, and both types of quotation marks.

How severe is CVE-2026-66921?

CVE-2026-66921 has a CVSS score of 6.3/10 (MEDIUM severity). The EPSS model estimates a 0.28% probability of exploitation in the next 30 days.

How do I fix CVE-2026-66921?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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