Week in review: GitHub breached via poisoned VS Code extension, critical NGINX flaw exploited
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-45498 +1 in the same advisory: …41091 | Denial-of-Service Vulnerability in Microsoft Defender Antimalware Platform CVE-2026-45498 is a denial-of-service flaw (CWE-400, uncontrolled resource consumption) in the Microsoft Defender antimalware platform, rated 7.5 (High) with a network attack vector and no privileges or user interaction required. A remote, unauthenticated attacker can trigger excessive resource consumption that disrupts the Defender service, with high impact on availability but no confidentiality or integrity impact per the CVSS scoring. An attacker gains the ability to crash, hang, or disable antimalware protection on targeted systems, potentially leaving endpoints temporarily unprotected. Any deployment of Microsoft Defender — which is the default antimalware on modern Windows and is also deployed as a cloud service — is in scope, and CISA's required action explicitly points defenders to BOD 22-01 guidance for cloud services. The flaw has been added to CISA's KEV catalog (2026-05-20), EPSS assigns it a 63.1% probability of exploitation within 30 days, and headlines confirm it is being exploited in the wild alongside CVE-2026-41091. Do: Apply mitigations per Microsoft's vendor instructions and follow applicable CISA BOD 22-01 guidance for cloud services, as required by the KEV entry. Ensure the Defender antimalware platform and its security intelligence updates are fully current on all endpoints, and check event logs for Defender service crashes or disabled protection that may indicate exploitation. Ransomware use is currently listed as unknown, so treat any Defender outage on exposed systems as a potential precursor to follow-on activity. | 7.5 group max | 63% | KEV |
| masshundreds of millions of Windows endpoints (Defender is the default antimalware on modern Windows client and server) | |
| CVE-2026-42945 | Heap Buffer Overflow in NGINX Plus & Open Source rewrite module — DoS, potential RCE NGINX Plus and NGINX Open Source contain a heap buffer overflow (CWE-122, from an incorrect buffer size calculation per CWE-131) in the ngx_http_rewrite_module, triggered when a rewrite directive is followed by a rewrite, if, or set directive and an unnamed PCRE capture (e.g., $1, $2) whose replacement string includes a question mark. An unauthenticated remote attacker can trigger the flaw with crafted HTTP requests, but only on servers whose configuration includes this specific directive pattern — hence the high-attack-complexity rating despite the 9.2 CVSS v4.0 score. Successful exploitation causes a heap overflow in the NGINX worker process, crashing it and forcing a restart (availability impact), and can result in code execution on hosts where ASLR is disabled or can be bypassed. All F5 NGINX products built on the NGINX codebase are affected — NGINX Plus, NGINX Open Source, NGINX Ingress Controller, NGINX Gateway Fabric, NGINX Instance Manager, NGINX WAF, and NGINX App Protect DoS — while versions past End of Technical Support were not evaluated. Exploitation has not yet been confirmed in the wild and the flaw is not in CISA KEV, but a public proof-of-concept ('Nginx-Rift') is available and EPSS assigns a 68% probability of exploitation within 30 days (99th percentile). Do: Upgrade NGINX Plus, NGINX Open Source, and each affected F5 NGINX-derived product (Ingress Controller, Gateway Fabric, Instance Manager, WAF, App Protect DoS) to the patched releases listed in F5's security advisory, noting that EoTS versions were not evaluated and need separate remediation. Interim mitigation: audit nginx configurations for rewrite directives chained with another rewrite, if, or set where unnamed captures ($1, $2, ...) appear in a replacement string containing '?', and remove or restructure those directives (e.g., drop the trailing '?'). Prioritize systems with ASLR disabled, where exploitation could yield remote code execution rather than just a worker-process crash/restart. | 9.2 | 68% | PoC |
| mass≈1,000,000+ internet-exposed NGINX deployments potentially in scope (a smaller subset with the specific rewrite/if/set + unnamed-capture + '?' configuration is… | |
| CVE-2026-45585 | Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as "YellowKey". Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as "YellowKey". The proof of concept for this vulnerability has been made public violating coordinated vulnerability best practices. We are issuing this CVE to provide mitigation guidance that can be implemented to protect against this vulnerability until the security update is made available. Mitigation FAQs Should I leverage the temporary mitigation? Microsoft recommends that you consider implementing these mitigations if you are concerned your devices and data are at risk of being compromised or stolen. For example, if your organization’s employees take their work devices home or on business travel. What impact to service availability/management could be caused by implementing the mitigations? Implementing these mitigations will not impact service availability or management operations. Do customers need to revert the changes made to mitigate the vulnerability once the security update to protect against this vulnerability is available? No. The security update will maintain the mitigation's behavior once the security update is installed. I am using TPM+PIN, am I at risk of this vulnerability being exploited No, if you are using TPM+PIN the vulnerability is not exploitable. NVD description · AI analysis pending | 6.8 | 1% | PoC |
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Full article1,148 words · extracted from helpnetsecurity.com · click to collapse
Here’s an overview of some of last week’s most interesting news, articles, interviews and videos:
GitHub, Grafana Labs breaches traced back to TanStack supply chain compromise
GitHub CISO Alexis Wales has named the malicious VS Code extension behind the breach they suffered at the hands of the threat group TeamPCP: Nx Console, a popular developer tool with 2.2 million installs.
Earbud sensors can authenticate users by their heartbeat, study finds
Researchers built a continuous authentication system called AccLock that identifies a wearer by the tiny vibrations a heartbeat makes inside the ear canal.
Attackers are exploiting critical NGINX vulnerability (CVE-2026-42945)
A critical NGINX vulnerability (CVE-2026-42945) disclosed last week is being exploited by attackers, VulnCheck security researcher Patrick Garrity revealed on Saturday.
Communicating cyber risk in dollars boards understand
In this Help Net Security interview, Nick Nieuwenhuis, Cybersecurity Architect at Nedscaper, explains why cybersecurity has not delivered the resilience that decades of investment have promised.
Microsoft provides mitigation for “YellowKey” BitLocker bypass flaw (CVE-2026-45585)
Microsoft is working on a fix for CVE-2026-45585 (aka “Yellowkey”), a vulnerability that can be used by attackers to bypass protections offered by BitLocker, the full-disk encryption feature built into Windows, and access users’ data.
Why AI changed the threat model for travel technology
In this Help Net Security interview, Devon Bryan, SVP, Global CSO at Booking Holdings, reflects on his path from Air Force network security engineer to global CSO across financial services, hospitality, and travel technology.
Deleted Google API keys keep working for up to 23 minutes, researchers warn
Google API keys are credentials that let applications access Google services, from Maps to the Gemini AI. If a key is leaked, an attacker can use it to make API calls, rack up charges, and, if Gemini is enabled, access uploaded files and cached conversations. The assumed fix is simple: delete the key. But Aikido Security has found that deletion doesn’t actually work right away.
Microsoft open-sources tools for designing and testing AI agents
Microsoft has open-sourced two tools aimed at bringing security discipline to AI agent development: Clarity, a structured design review tool, and RAMPART, a continuous testing framework.
AI red teaming agents change how LLMs get tested
Adversarial probing of LLMs has piled up a sprawling toolkit over the past three years. Attack techniques with names like Tree of Attacks with Pruning, Crescendo, and Skeleton Key sit alongside hundreds of prompt transforms and scoring methods across open-source frameworks including Microsoft’s PyRIT, NVIDIA’s Garak, and Promptfoo.
Microsoft Defender vulnerabilities exploited in the wild (CVE-2026-41091, CVE-2026-45498)
Attackers are exploiting two Microsoft Defender vulnerabilities (CVE-2026-41091 and CVE-2026-45498), Microsoft acknowledged and CISA confirmed by adding them to its Known Exploited Vulnerabilities catalog.
Verizon DBIR: Vulnerability exploitation is the dominant initial access vector
Vulnerability exploitation has overtaken stolen credentials as the most common way attackers gain initial access to target networks, according to the 2026 Verizon Data Breach Investigations Report.
PureLogs infostealer is stealing credentials worldwide
A phishing campaign is smuggling the powerful PureLogs information stealer onto targets’ Windows machines by hiding encrypted malicious payloads inside cat photos, Fortinet researchers discovered.
New macOS infostealer impersonates Apple, Microsoft, and Google in a single attack chain
A SHub macOS infostealer variant called Reaper impersonates Apple, Microsoft, and Google to trick users into executing malicious code, then targets browser data, password managers, and cryptocurrency wallets while establishing persistence for continued access, SentinelOne found.
AI is drowning software maintainers in junk security reports
AI-assisted vulnerability research has exploded, unleashing a firehose of low-quality reports on overworked software maintainers who are wasting hours sifting through noise instead of fixing real problems.
The end of unencrypted Discord calls is here
Discord has protected voice and video calls in DMs, group DMs, voice channels, and Go Live streams with end-to-end encryption (E2EE) by default.
The AI backdoor your security stack is not built to see
Enterprises deploying LLMs have spent the past two years building defenses around a reasonable assumption: malicious behavior leaves a trace in the input. Scan for suspicious tokens, filter unusual characters, watch for prompt injection patterns. New research from Microsoft and the Institute of Science Tokyo demonstrates that this defensive posture has a blind spot, and the cost of that blind spot could be measured in leaked proprietary data and regulatory exposure.
When ransomware hits, confidence doesn’t restore endpoints
Ransomware, supply chain vulnerabilities, insider threats, compliance failures, and software disruptions remain major concerns for security leaders, according to The Ransomware Reality: Zero Days to Recover report by Absolute Security.
AI shrinks vulnerability exploitation window to hours
Time has become organizations’ biggest vulnerability because the gap between vulnerability discovery and exploitation has narrowed to hours, according to Synack’s 2026 State of Vulnerabilities Report.
Most dark web activity revolves around a handful of topics
A six-year dataset covering more than 25,000 dark web sites tracked what people discussed in underground forums and marketplaces and how those discussions changed over time.
Public Instagram posts provide raw material for AI phishing campaigns
A handful of public Instagram posts can give attackers enough material to generate convincing phishing emails with GenAI. Research from the University of Texas at Arlington and Louisiana State University showed how public social media activity can be turned into phishing messages that appear personal and credible to human recipients.
CVE Lite CLI: Open-source dependency vulnerability scanner
Dependency vulnerability scanning in JavaScript and TypeScript projects has long sat at the end of the development pipeline. Pull requests get opened, continuous integration runs, and a security scanner returns a list of CVE identifiers that developers then have to triage hours or days after writing the code. CVE Lite CLI, now an officially recognized OWASP Incubator Project, moves that check to the developer’s terminal.
What happens when your identity provider becomes the kill chain
In this Help Net Security video, Colin Constable, CTO at Atsign, explains why your identity provider (IdP) has become the kill chain in cyberattacks. Attackers steal session cookies, tokens, or consent grants you’ve already issued and walk in behind you.
7 hard truths security pros should know: 2026 DevOps Threats Report
In 2025, trusted Git hosting platforms became a playground for cyber criminals. This is the main conclusion from the latest “DevOps Threat Unwrapped Report 2026” by GitProtect.
Product showcase: Bitdefender Mobile Security for iOS protects privacy where scams begin
Bitdefender Mobile Security for iOS is a security and privacy application for iPhone and iPad that helps protect against phishing attempts, online scams, unsafe websites, and account exposure.
Cybersecurity jobs available right now: May 19, 2026
We’ve scoured the market to bring you a selection of roles that span various skill levels within the cybersecurity field. Check out this weekly selection of cybersecurity jobs available right now.
New infosec products of the week: May 22, 2026
Here’s a look at the most interesting products from the past week, featuring releases from ASAPP, Babel Street, CTERA, Forward, Riverbed, and Trust3 AI.
Text extracted automatically; images, tables and formatting may be missing. Original: https://www.helpnetsecurity.com/2026/05/24/week-in-review-github-breached-via-poisoned-vs-code-extension-critical-nginx-flaw-exploited/