CVE-2026-26201

emp3r0r Affected by Concurrent Map Access DoS (panic/crash)

Published Feb 19, 2026 CVSS 4.0 · 7 High EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

Emp3r0r is a command‑and‑control tool written in Go that uses shared maps across goroutines. Prior to version 3.21.2, the tool does not guard concurrent reads and writes against these maps, creating a race condition that can trigger the Go runtime fatal error "concurrent map read and map write". When this occurs the C2 process panics and terminates, resulting in a loss of availability for the compromised host. This vulnerability is a classic race‑condition flaw (CWE‑362/CWE‑663).

Affected Systems

The bug appears in all releases of emp3r0r before v3.21.2. The affected product is the command‑and‑control framework developed by jm33-m0 (username). All systems running a vulnerable version are susceptible to crash under concurrent map access.

Risk and Exploitability

The CVSS score of 7 indicates high severity. EPSS is less than 1%, suggesting exploitation is unlikely but not impossible. The CWE identifiers point to a race condition that requires concurrent goroutine activity. Attackers would typically need to trigger a high‑concurrency scenario within the C2 process; external network traffic alone may not be sufficient. The vulnerability is not listed in the CISA KEV catalog, meaning no public exploits have been observed yet. The risk remains for systems running older emp3r0r versions that cannot be immediately patched.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade emp3r0r to version 3.21.2 or later
  • Ensure all running instances are updated before restarting activities
  • If upgrade is delayed, throttle concurrent commands or configure serial processing to avoid map contention

Generated by OpenCVE AI on April 17, 2026 at 17:57 UTC.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-f5p9-j34q-pwcc emp3r0r Affected by Concurrent Map Access DoS (panic/crash)
History
Type Values Removed Values Added
CPEs cpe:2.3:a:jm33-m0:emp3r0r:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
First Time appeared Jm33-m0
Jm33-m0 emp3r0r
Vendors & Products Jm33-m0
Jm33-m0 emp3r0r
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title emp3r0r Affected by Concurrent Map Access DoS (panic/crash)
Weaknesses CWE-362
CWE-663
References
Metrics cvssV4_0

{'score': 7, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H'}

Weaknesses
  • CWE-362

    Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

  • CWE-663

    Use of a Non-reentrant Function in a Concurrent Context

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Feb 19, 2026, 9:22 PM
Reserved
Feb 11, 2026, 7:56 PM
Status
Analyzed
Published
Feb 19, 2026, 8:25 PM
Modified
Jun 17, 2026, 10:25 AM