VulnerabilityAnalyzed

CVE-2026-26201

Under concurrent activity, Go runtime can trigger `fatal error: concurrent map read and map write`, causing C2 process crash (availability loss).

HIGH 7.0EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 7.0 HIGHCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.29% probability · 22th percentile
CISA KEV: Not listed
Weakness: CWE-362, CWE-663
Affected: jm33-m0/emp3r0r
Source: security-advisories@github.com

References

https://github.com/jm33-m0/emp3r0r/commit/ea4d074f081dac6293f3aec38f01def5f08d5af5Patch
https://github.com/jm33-m0/emp3r0r/releases/tag/v3.21.2Product, Release Notes
https://github.com/jm33-m0/emp3r0r/security/advisories/GHSA-f5p9-j34q-pwccExploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.