Loki Intelligence — Security Briefs · Published
Daily Brief: AI Gateway RCE, Edge Appliance KEVs, and Defender Update Blocking
Today's risk spans unauthenticated access to AI infrastructure, exploited edge and network appliances, and tooling that can quietly weaken endpoint protection. Teams should patch KEV-listed Check Point, Arista, F5 and Zyxel systems, lock down AI gateway management APIs, and monitor Defender update health.
Signal 01 · The Hacker News
Critical Bifrost AI Gateway Flaw Lets Attackers Run Commands Without Credentials
JFrog disclosed CVE-2026-90898 (CVSS 9.8) in Bifrost, an open-source AI gateway whose management API ships without authentication by default, letting an attacker register a stdio MCP client that immediately runs a chosen command. That exposes stored LLM provider API keys. Versions before transports v2.1.0 are affected; the maintainer disputes the severity rating.
Why it matters: Upgrade to v2.1.0, enable management authentication, keep the API off untrusted networks, and rotate provider and virtual keys if an exposed instance ran unauthenticated.
Source: The Hacker News
Signal 02 · CISA
CISA Adds Four Known Exploited Vulnerabilities to Catalog
CISA added four actively exploited vulnerabilities to its KEV catalog: two Check Point flaws covering improper certificate validation (CVE-2026-85102) and path traversal (CVE-2026-93616), an Arista VeloCloud Orchestrator input validation flaw (CVE-2026-93952), and an F5 BIG-IP APM heap-based buffer overflow (CVE-2026-94127).
Why it matters: These are perimeter and SD-WAN management systems; apply vendor fixes or mitigations quickly, limit their exposure, and review logs for signs of compromise before and after patching.
Source: CISA
Signal 03 · The Hacker News
Researcher Drops BigDiskBuster Zero-Day PoC That Blocks Microsoft Defender Updates
A researcher published BigDiskBuster, an unpatched proof-of-concept that makes Microsoft Defender platform and signature updates fail by filling free disk space while an update downloads. Defender keeps running but its detection content goes stale. There is no CVE or Microsoft advisory, and the claimed behavior has not been independently confirmed.
Why it matters: Alert on repeated Defender update failures and sustained low system disk space, verify signature versions centrally, and use WDAC or AppLocker to block unknown binaries.
Source: The Hacker News
Signal 04 · CISA
CISA Adds One Known Exploited Vulnerability to Catalog
CISA's September 21 update added CVE-2026-7273 to the KEV catalog, a stack-based buffer overflow affecting Zyxel GS1900 series switches, citing evidence of active exploitation. The alert repeats CISA's call for all organizations to fold catalog entries into risk-based patch prioritization.
Why it matters: LAN-side switches still need urgent firmware updates once exploited; confirm GS1900 versions and limit web management access to dedicated admin segments.
Source: CISA
Signal 05 · The Hacker News
Zyxel and Veeam Flaws Under Active Exploitation With Command and SYSTEM Access
GreyNoise reports a suspected Chinese-speaking actor exploiting Zyxel GS1900 flaw CVE-2026-7273 since August 17, pulling configurations and hashed credentials from 996 switches in 48 countries. Separately, Arctic Wolf warned of active exploitation of CVE-2026-32996, a Veeam Agent for Microsoft Windows flaw that gives local attackers SYSTEM-level control.
Why it matters: Patch GS1900 firmware and rotate switch credentials where compromise is suspected; check Veeam's guidance for Agent for Windows and watch endpoints for unexpected SYSTEM commands.
Source: The Hacker News
Signal 06 · CISA
Siemens SIPLUS and SIMATIC Products
Siemens reports that many SIMATIC and SIPLUS products, including Unified HMI panels, CN 4100, IoT2050 Advanced and Industrial Edge Device OS, are affected by the Linux kernel 'Copy Fail' flaw CVE-2026-31431 (CVSS 7.8, local access). Fixes exist for some products, while others await updates and have interim countermeasures.
Why it matters: Inventory affected Siemens devices, apply available updates, and limit shell access to trusted personnel and applications to trusted sources until remaining fixes ship.
Source: CISA
Signal 07 · CISA
Siemens Siveillance Control
Siemens Siveillance Control and Control Pro versions 3.x and 4.x contain CVE-2026-50093 (CVSS 9.0), an arbitrary file upload flaw in the Open Interface Services web module that could give an attacker root access on the OIS server. Siemens has released fixed builds for each affected product line.
Why it matters: Update OIS to the fixed builds and keep these security management servers on segmented networks reachable only by authorized operators.
Source: CISA
Brief sources
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Relevant Loki services: Orvyn — AI agent security private preview and SKYEN web & API pentesting.