CVE-2026-44451

CRITICAL
Published May 26, 2026 Modified May 27, 2026 CWE-693

Description

Lumiverse is a full-featured AI chat application. Prior to 0.9.7, the component override system transpiles user-supplied TSX via Sucrase and evaluates it with new Function, shadowing dangerous globals (fetch, window, eval, etc.) with undefined. A static source validator (validateComponentOverrideSource) additionally blocks these identifiers by word-boundary regex. Both controls are bypassed. String-split bypass of the static validator: any blocked identifier can be reconstructed at runtime from string fragments ('ownerDoc' + 'ument'). DOM ref escape from the sandbox: useRef and useEffect are provided in scope. A ref attached to a rendered element gives a live DOM node. From any real DOM node, node['ownerDoc'+'ument']['def'+'aultView'] yields the real window, bypassing all identifier shadows. Theme packs (.lumitheme / .lumiverse-theme) are the shareable delivery mechanism. A malicious pack is an exploit path: the victim imports the file, enables one component override in the Theme Editor, and the payload fires in their authenticated session.This vulnerability is fixed in 0.9.7.

CVSS v3.1 Score

9.3
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0004
Probability of exploitation
0.12%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-693 CWE-693

References

Frequently Asked Questions

What is CVE-2026-44451? +
Lumiverse is a full-featured AI chat application. Prior to 0.9.7, the component override system transpiles user-supplied TSX via Sucrase and evaluates it with new Function, shadowing dangerous globals (fetch, window, eval, etc.) with undefined. A static source validator (validateComponentOverrideSource) additionally blocks these identifiers by word-boundary regex. Both controls are bypassed. String-split bypass of the static validator: any blocked identifier can be reconstructed at runtime from string fragments ('ownerDoc' + 'ument'). DOM ref escape from the sandbox: useRef and useEffect are provided in scope. A ref attached to a rendered element gives a live DOM node. From any real DOM node, node['ownerDoc'+'ument']['def'+'aultView'] yields the real window, bypassing all identifier shadows. Theme packs (.lumitheme / .lumiverse-theme) are the shareable delivery mechanism. A malicious pack is an exploit path: the victim imports the file, enables one component override in the Theme Editor, and the payload fires in their authenticated session.This vulnerability is fixed in 0.9.7. It has a CVSS v3.1 base score of 9.3 (CRITICAL).
How severe is CVE-2026-44451? +
CVE-2026-44451 has a CVSS v3.1 score of 9.3 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0004, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-44451? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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