CVE-2026-26201: jm33-m0 emp3r0r · Race Condition
Affects jm33-m0 emp3r0rSource CVE Database V5
Not known to be exploited · CVSS 7.0 High : upgrade to 3.21.2 soon.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.21.2
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade jm33-m0 emp3r0r to 3.21.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| jm33-m0emp3r0r | Affected
| Fixed in
|
AI-suggested
The definitive mitigation for CVE-2026-26201 is to upgrade emp3r0r to version 3.21.2 or later, where proper synchronization mechanisms have been implemented to prevent concurrent map access. Organizations should audit their use of emp3r0r and ensure no legacy versions remain in production or testing environments. Additionally, developers and operators should review concurrent data structure usage in all Go-based security tools to enforce thread safety, employing synchronization primitives such as mutexes or channels as appropriate. Implementing robust monitoring and alerting on C2 process crashes can provide early detection of exploitation attempts. Network segmentation and strict access controls limiting who can authenticate to the C2 server reduce the risk of exploitation. Finally, conducting regular code reviews and fuzz testing for concurrency issues in security-critical software can prevent similar vulnerabilities in the future.
Description
emp3r0r is a C2 designed by Linux users for Linux environments. Prior to version 3.21.2, multiple shared maps are accessed without consistent synchronization across goroutines. Under concurrent activity, Go runtime can trigger `fatal error: concurrent map read and map write`, causing C2 process crash (availability loss). Version 3.21.2 fixes this issue.