CVE-2024-51749: Element's thumbnails can be abused to misrepresent the content of an attachment

Severity: low (CVSS 3.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-11-12 · updated 2026-06-17
Weakness: CWE-451

Description

Element is a Matrix web client built using the Matrix React SDK. Versions of Element Web and Desktop earlier than 1.11.85 do not check if thumbnails for attachments, stickers and images are coherent. It is possible to add thumbnails to events trigger a file download once clicked. Fixed in element-web 1.11.85.

Affected products

element-hq element-web: before 1.11.85

References

https://github.com/element-hq/element-web/commit/a00c343435d633e64de2c0548217aa611c7bbef5
https://github.com/element-hq/element-web/security/advisories/GHSA-5486-384g-mcx2

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