CVE-2026-110611

REBUILD through 4.5.0 contains an authorization bypass vulnerability in AiBot2Controller /aibot2 endpoints that act on a caller-supplied chatid without verifying ownership. Authenticated low-privilege users can supply another user's chatid to chat-init, chat-delete, chat-feedback, or chat-stream-stop to read, delete, exfiltrate, or interrupt AI assistant conversations.

CVSS 4.0

6.0CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

5.9CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 31% of CVEs (scores of 2026-10-25)

CWE

CWE-639

Published

2026-10-14

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

References

• https://github.com/getrebuild/rebuild/blob/48c6cc42f9c331cc57c057fa9c66d6cbda990131/src/main/java/com/rebuild/core/aibot2/ChatManager.java#L99-L101
• https://github.com/getrebuild/rebuild/blob/48c6cc42f9c331cc57c057fa9c66d6cbda990131/src/main/java/com/rebuild/web/aibot/AiBot2Controller.java#L151-L203
• https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/getrebuild-rebuild-aibot-chat-idor
• https://www.vulncheck.com/advisories/rebuild-through-4.5.0-authorization-bypass-via-aibot2-chat-endpoints-chatid
• https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/getrebuild-rebuild-aibot-chat-idor

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