CVE-2026-26201: emp3r0r Affected by Concurrent Map Access DoS (panic/crash)

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-02-19 · updated 2026-06-17
Weakness: CWE-362

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.

Affected products

jm33-m0 emp3r0r: before 3.21.2 — fixed in 3.21.2

How to fix

Upgrade to a fixed version: jm33-m0 emp3r0r 3.21.2. Check the vendor advisory for mitigations.

References

https://github.com/jm33-m0/emp3r0r/commit/ea4d074f081dac6293f3aec38f01def5f08d5af5
https://github.com/jm33-m0/emp3r0r/releases/tag/v3.21.2
https://github.com/jm33-m0/emp3r0r/security/advisories/GHSA-f5p9-j34q-pwcc

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