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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.0 · 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 · score source

EPSS

• CVE-2026-26201: 0.33% estimated exploitation activity in the next 30 days; percentile 26.43 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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). Vulnerable Component(with code examples) Operator relay map had mixed access patterns (iteration and mutation without a single lock policy): Port-forwarding session map had read/write paths guarded inconsistently: FTP stream map similarly mixed concurrent iteration with mutation: Attack Vector 1. Attacker (or stress traffic in authenticated flows) triggers high concurrency in normal control paths. 2. Operator sessions connect/disconnect while message forwarding and file-transfer workflows are active. 3. Concurrent read/write hits shared maps. 4. Go runtime panics with concurrent map read/write error. 5. C2 component exits, producing denial of service. Proof of Concept 1. Start C2 server with active operator session(s) in a lab environment. 2.…

Published by the source

17 Feb 2026, 21:27 UTC

Last modified by the source

19 Feb 2026, 21:56 UTC

Source last checked

26 Oct 2026, 15:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-f5p9-j34q-pwcc

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# Patch Next advisory brief: CVE-2026-26201

Advisory: emp3r0r Affected by Concurrent Map Access DoS (panic/crash)
IDs: CVE-2026-26201, GHSA-f5p9-j34q-pwcc
Record: https://patchnext.com/advisories/cve-2026-26201 (revision 1, source checked 26 Oct 2026, 15:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/jm33-m0/emp3r0r/core 0.0.0-20260212232424-ea4d074f081d. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/jm33-m0/emp3r0r/core: affected < 0.0.0-20260212232424-ea4d074f081d; fixed in 0.0.0-20260212232424-ea4d074f081d

## Suggested inspection (read-only)
- Go github.com/jm33-m0/emp3r0r/core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/jm33-m0/emp3r0r/core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-f5p9-j34q-pwcc (GitHub-reviewed advisory GHSA-f5p9-j34q-pwcc lists affected ranges: Go github.com/jm33-m0/emp3r0r/core >=0 <0.0.0-20260212232424-ea4d074f081d)

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