CVE-2026-108725

Cheshire Cat AI core through 2.0.23 contains a stored cross-site scripting vulnerability in the uploads plugin that allows authenticated users to upload HTML files via POST /uploads without type restrictions. Attackers can send the public GET /uploads/{path} URL to a signed-in victim, executing script in the application origin with the victim's access_token cookie, including administrators.

CVSS 4.0

5.1CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CVSS 3.1

5.4CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 18% of CVEs (scores of 2026-10-25)

CWE

CWE-79

Published

2026-10-11

Modified

2026-10-16

Record from

the NVD, synced 2026-10-19

References

• https://github.com/cheshire-cat-ai/core
• https://github.com/cheshire-cat-ai/core/blob/c22731e7009ac89835b1d7b1cabc5989d998ec3e/src/cat/scaffold/plugins/uploads/endpoints.py#L28-L96
• https://hackmd.io/@haind03/cheshire-cat-uploads-stored-html-same-origin-xss
• https://www.vulncheck.com/advisories/cheshire-cat-ai-core-through-2.0.23-stored-xss-via-uploads-plugin
• https://hackmd.io/@haind03/cheshire-cat-uploads-stored-html-same-origin-xss

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