MuseBot: Use of Default Cryptographic Key
CVE-2026-119660 is a critical-severity use of default cryptographic key vulnerability in MuseBot from Yincongcyincong, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.0.0 as the first without the flaw, so updating MuseBot to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.52% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update MuseBot to 2.0.0 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Yincongcyincong | MuseBot | before 2.0.0 | 2.0.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 9.8 | Critical | CNA (vulncheck.com) |
Official description
MuseBot before 2.0.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge admin sessions by using the hard-coded default session_key 'muse_bot_session_key'. Attackers can sign a MuseBot-session cookie carrying a user_id to gain full administrative access, reading password hashes, chat records, and bot configuration, and stopping bots.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Default Cryptographic Key
The product uses a default cryptographic key for potentially critical functionality.
How developers prevent this class of flaw
- Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations.
- Force the administrator to change the credential upon installation.
- The product administrator could change the defaults upon installation or during operation.
More Use of Default Cryptographic Key vulnerabilities (CWE-1394)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
- github.com/yincongcyincong/MuseBot
- github.com/yincongcyincong/MuseBot/blob/v1.0.42/admin/conf/conf.go#L28
- github.com/yincongcyincong/MuseBot/blob/v1.0.42/admin/controller/login.go#L19-L88
- github.com/yincongcyincong/MuseBot/issues/61
- hackmd.io/@hieuPenguinnn/musebot-admin-default-session-key-auth-bypass
- vulncheck.com/advisories/musebot-before-2.0.0-authentication-bypass-via-hard-coded-session-key
Recent Use of Default Cryptographic Key vulnerabilities
- 7.7 High severity
- 8.8 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 8.1 High severity
- 9.1 Critical severity
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