CVE-2026-118691
xianyu-auto-reply-fix through 2.0.7 Unauthenticated Message Sending via /send-message
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST /send-message endpoint that allows unauthenticated attackers to send messages from other users' accounts using publicly known default API secrets. Attackers can supply the hard-coded api_key and another user's cookie_id, plus chosen chat_id, to_user_id and message values, to send arbitrary Xianyu messages to buyers from that merchant account.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
xianyu-auto-reply-fix through 2.0.7 Unauthenticated Message Sending via /send-message
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST /send-message endpoint that allows unauthenticated attackers to send messages from other users' accounts using publicly known default API secrets. Attackers can supply the hard-coded api_key and another user's cookie_id, plus chosen chat_id, to_user_id and message values, to send arbitrary Xianyu messages to buyers from that merchant account.
- Record
CVE-2026-118691- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-1188
- Updated
- 2026-11-03
EUVDEUVD-2026-112492
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST /send-message endpoint that allows unauthenticated attackers to send messages from other users' accounts using publicly known default API secrets. Attackers can supply the hard-coded api_key and another user's cookie_id, plus chosen chat_id, to_user_id and message values, to send arbitrary Xianyu messages to buyers from that merchant account.
- Record
EUVD-2026-112492- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8xg3-rxxw-rm99
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST ...
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST /send-message endpoint that allows unauthenticated attackers to send messages from other users' accounts using publicly known default API secrets. Attackers can supply the hard-coded api_key and another user's cookie_id, plus chosen chat_id, to_user_id and message values, to send arbitrary Xianyu messages to buyers from that merchant account.
- Record
GHSA-8xg3-rxxw-rm99- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/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 - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-1188
- Updated
- 2026-11-03
NVD
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST /send-message endpoint that allows unauthenticated attackers to send messages from other users' accounts using publicly known default API secrets. Attackers can supply the hard-coded api_key and another user's cookie_id, plus chosen chat_id, to_user_id and message values, to send arbitrary Xianyu messages to buyers from that merchant account.
- Record
CVE-2026-118691- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/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 - CVSS 3.1
- 3.7 Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-1188
- Updated
- 2026-11-03
OSV
xianyu-auto-reply-fix through 2.0.7 Unauthenticated Message Sending via /send-message
xianyu-auto-reply-fix through 2.0.7 contains a missing authorization vulnerability in the POST /send-message endpoint that allows unauthenticated attackers to send messages from other users' accounts using publicly known default API secrets. Attackers can supply the hard-coded api_key and another user's cookie_id, plus chosen chat_id, to_user_id and message values, to send arbitrary Xianyu messages to buyers from that merchant account.
- Record
CVE-2026-118691- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-1188
- Updated
- 2026-11-07
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| references | NVD, OSV | |
| references | CVE List | |
| references | GitHub Advisories | |
| facts | EUVD | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-118691 is a medium vulnerability (CVSS 6.3) in Gudong2003 Xianyu-auto-reply-fix, published October 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.32%, the 24th percentile. No source names a fixed version.
References
github.com/GuDong2003/xianyu-auto-reply-fix/issues/116
vulncheck.com/advisories/xianyu-auto-reply-fix-through-2.0.7-unauthenticated-message-sending-via-send-message