---
title: "Security digest: October 4, 2026"
url: https://erroneo.us/security/2026-10-04/
description: "October 4, 2026 vulnerability digest: 1 brief (AhsayCBS: Exploited Pre-Auth RCE Chain in Backup…); 1 CISA KEV addition (Citrix). What to patch and who can…"
type: security-digest-day
section: "Security Digest"
date_published: 2026-10-04
date_modified: 2026-10-15
publisher: erroneo.us
author: erroneo.us Security Desk
license: All rights reserved. Quote with attribution and a link.
---

# Security digest: October 4, 2026

1 editorial brief and 1 known exploited (cisa kev) addition.

## Take stock

- Act now: AhsayCBS: Exploited Pre-Auth RCE Chain in Backup Server . MSPs, system integrators and companies running AhsayCBS v7 through v10 below 10.3.4.45 or 9.15.2.70, including servers that already applied 10.3.4.0 or 9.15.2.59.
- Do you run any of these? Citrix NetScaler. They are being exploited in the wild (CISA KEV). Patch or mitigate if you do; CISA’s federal deadline is 2026-10-07.
- None of it touches your stack? Then there is nothing to do today. That is a result, not a failure to read carefully.

## Editorial briefs

- **Act now** [AhsayCBS: Exploited Pre-Auth RCE Chain in Backup Server](https://erroneo.us/security/briefs/ahsaycbs-cve-2026-105133-105134-backup-server-rce/index.md): If you or your MSP run an AhsayCBS backup server, install the October 12 hotfix today and hunt for webshells: the chain is unauthenticated, runs as SYSTEM, is being exploited by several actors, and the August patch did not fix it.

## Known exploited (CISA KEV)

- [CVE-2026-88779](https://erroneo.us/security/cve/CVE-2026-88779/index.md) Citrix NetScaler: Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability (CISA due 2026-10-07)

## Critical advisories

None.

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Source page: https://erroneo.us/security/2026-10-04/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt