Saturday, October 3, 2026|Issue 12|6 min read|Join the discussion

Old exposure is becoming today's ransomware incident

New reporting on Warlock shows attackers still turning long-patched SharePoint weaknesses into critical-infrastructure compromise, while FortiMail and Cisco SD-WAN remain immediate remediation priorities. At the same time, AWS is moving cloud architecture review from a periodic checklist toward an AI agent that can recommend, and sometimes generate, the remediation itself.

The short version

  • Warlock (Symantec: Longlegs; Microsoft: Storm-2603) is still breaking in through on-premises SharePoint, hitting a water utility, a telecom provider, a regional government body and a university.
  • Cisco Catalyst SD-WAN Manager CVE-2026-76504: exploited authentication bypass to admin API access. The federal deadline is today.
  • Fortinet FortiMail CVE-2026-104286: exploited unauthenticated arbitrary file write. The federal deadline is tomorrow, October 4.
  • AWS launched the Well-Architected Agent in preview: continuous architecture review with ready-to-run remediation.
  • Remediation isn't done when the ticket closes. It's done when the exposure is gone.

Issue at a glance

3 critical

  1. criticalRansomwareWarlock is still turning SharePoint exposure into ransomware
  2. criticalPolicyCisco SD-WAN's federal remediation deadline is today
  3. criticalNetworkFortiMail remains under active attack as the October 4 deadline approaches

Patch clock

Added 2026-10-01Due 2026-10-04
Today marker at day 3 of 3Federal deadline passed 41 days ago
CVEProductWhat it isSeverity
CVE-2026-76504Cisco Catalyst SD-WAN ManagerAuthentication bypass giving unauthenticated admin API access. Due today, October 3Critical (CVSS 9.8), KEV, exploited
CVE-2026-104286Fortinet FortiMailUnauthenticated arbitrary file write. Due tomorrow, October 4Critical (CVSS 9.8), KEV, exploited

Also on the vulnerability desk

  • Carryover: ConnectWise ScreenConnect CVE-2026-84869, patched in 26.6.5 on September 8. A client flaw can allow files to be transferred and executed through an active remote session without host authorization or confirmation in certain circumstances; servers are not affected. CISA added it to KEV on September 11.

    ConnectWise bulletin|CISA

Fortinet PSIRT FG-IR-26-175|CISA|Cisco advisory cisco-sa-sdwan-webauth-xr8beuuU|Cisco remediation guide|CISA KEV catalog

Breaking

CriticalRansomware

ransomware / SharePoint / critical infrastructure

Warlock is still turning SharePoint exposure into ransomware

Symantec reports that the China-nexus group behind Warlock, which it tracks as Longlegs and Microsoft tracks as Storm-2603, attacked at least four organizations in the past two months: a water utility, a telecommunications provider, a regional government body and a university in Portuguese- and Spanish-speaking countries across Europe, Africa and Latin America. The group keeps favoring SharePoint vulnerabilities for initial access, the attack surface that made it notorious with the ToolShell chain (CVE-2025-49704, CVE-2025-49706, CVE-2025-53770, CVE-2025-53771), fixed more than a year ago. In one intrusion it disabled security software on at least 40 systems using the vulnerable, signed K7RKScan driver, then ran Warlock on at least 33.

Why it matters. Vulnerability age does not equal vulnerability irrelevance. Internet-facing systems that missed an old remediation window can stay useful to attackers for years.

What to do. Inventory on-premises SharePoint now and validate actual patch state, not closed tickets. Hunt for ASPX web shells and unusual __VIEWSTATE activity, investigate unexpected VS Code tunnels or remote-access tools, rotate ASP.NET machine keys on exposed servers, and make sure EDR tamper protection covers vulnerable-driver abuse. A closed vulnerability ticket is not proof that exposure was eliminated.

CVE-2025-49704, CVE-2025-49706, CVE-2025-53770, CVE-2025-53771

Symantec (security.com)

CriticalPolicy

Cisco / SD-WAN / KEV

Cisco SD-WAN's federal remediation deadline is today

CVE-2026-76504 lets an unauthenticated remote attacker bypass authentication in Cisco Catalyst SD-WAN Manager and reach the API as the admin user, through improper handling of URI encoding in HTTP requests. It affects all configurations, there is no workaround, and exploitation has been observed. CISA's federal deadline is October 3.

Why it matters. SD-WAN Manager controls connectivity between branches, cloud environments and data centers. Admin access there is control of the network fabric.

What to do. Upgrade to a fixed release, collect admin-tech files and follow Cisco's remediation guide to check for compromise, including suspicious URL-encoded requests to management endpoints. Treat it as incident response, not just maintenance.

CVE-2026-76504

Cisco advisory cisco-sa-sdwan-webauth-xr8beuuU|Cisco remediation guide|CISA KEV catalog

CriticalNetwork

Fortinet / email security / KEV

FortiMail remains under active attack as the October 4 deadline approaches

CVE-2026-104286 is a path-traversal and null-byte flaw in FortiMail that lets an unauthenticated attacker write arbitrary files via crafted HTTP or HTTPS requests. Fortinet says it has been exploited in the wild, and CISA added it to KEV on October 1 with an October 4 federal deadline. Fortinet lists the fixes as 8.0.2, 7.6.7 and 7.4.9; 7.2 users must move to 7.4 or later.

Why it matters. FortiMail sits on the inbound mail path. Arbitrary file write there can mean code execution on a trusted gateway.

What to do. Upgrade to the fixed release for your branch. Until then, apply Fortinet's workaround (disable IBE, or restrict webmail access to trusted networks), remove unnecessary public exposure, preserve evidence and check Fortinet's IOCs. Mitigated now does not mean never compromised.

CVE-2026-104286

Fortinet PSIRT FG-IR-26-175|CISA

Clearance corner

AI

BOD 26-04 in practice: today's and tomorrow's deadlines

October is Cybersecurity Awareness Month, but the bigger story is CISA's BOD 26-04 reshaping federal prioritization around actual risk. The Cisco and FortiMail deadlines show the model: known exploitation, exposure and technical impact drive remediation priority more than raw CVSS. For practitioners, the difference between vulnerability scanning and threat exposure management is explaining not only the CVE score but whether the asset is internet-facing, whether exploitation is confirmed, what the attack path is, what compensating controls exist and how remediation will be verified.

CISA BOD 26-04

What we are watching next

  • FortiMail

    October 4 deadline. Watch for fixed-build availability, more IOCs and the scale of CVE-2026-104286 exploitation.

  • Cisco SD-WAN

    Today's deadline may drive new incident discoveries; watch for victim reports and post-exploitation findings on CVE-2026-76504.

  • Warlock / Storm-2603

    Additional critical-infrastructure victims and evidence that other old SharePoint exposure remains exploitable.

  • AWS Well-Architected Agent

    How enterprises govern the move from AI-generated recommendations to executable SSM and IaC remediation.

  • AI infrastructure economics

    Power availability, permitting, financing and data-center opposition as constraints on expansion.

Sources

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Published Saturday, October 3, 2026. All issues