U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Apple macOS, Microsoft SharePoint, Broadcom VMware vCenter, and Microsoft IKE flaws to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added the following vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog: CVE-2026-33824 (CVSS score: 9.8) – Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Vulnerability CVE-2026-55040 (CVSS score: 9.1) Microsoft SharePoint Weak Authentication Vulnerability CVE-2026-59310 (CVSS score: 9.8) Broadcom VMware vCenter Path Traversal Vulnerability CVE-2026-65400 Apple macOS Improper Authentication Vulnerability CVE-2026-33824 is a Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability. This critical flaw in Windows IKE service extensions could allow remote attackers to execute code on affected systems. Systems with IKE enabled are at risk, though blocking UDP ports 500 and 4500 can reduce exposure from external threats. However, internal attackers may still exploit it for lateral movement, so rapid patching is strongly recommended. CVE-2026-55040 is a critical SharePoint authentication bypass. An unauthenticated attacker can exploit weaknesses in JWT validation to forge tokens and impersonate any SharePoint user, including administrators. “A critical authentication bypass vulnerability exists in SharePoint Server Subscription Edition’s JWT token validation pipeline. The root cause is a chain of four distinct weaknesses that, when combined, allow an unauthenticated remote attacker to forge a valid JWT and impersonate any SharePoint site user.” wrote Rapid7. The exploit chain works by sending a JWT with “alg: none” in the outer header so no signature is required, using SharePoint’s own STS certificate thumbprint to resolve a signing key without verification, and then passing a non-empty but never-verified signature like “AAAA.” The result is a fully forged token that SharePoint accepts as legitimate. Defused researchers observed attackers using the Rapid7 POC for CVE-2026-55040 against our SharePoint their honeypots. CVE-2026-59310 flaw is a Path Traversal Vulnerability that allows an attacker with network access to execute arbitrary code. “VMware vCenter contains a directory traversal vulnerability in the Syslog server. Broadcom has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.”states the advisory.”A malicious actor with network access to vCenter may exploit this issue to execute arbitrary code.” CVE-2026-65400 is an Improper Authentication Vulnerability that sits in macOS’s built-in Screen Sharing feature, the remote desktop tool baked into every Mac.On August 15, 2026, the Dutch National Cyber Security Centre confirmed active exploitation of a critical macOS authentication flaw, less than two weeks after Apple shipped the fix. Apple’s fix improved how the system manages authentication state, closing a gap that let attackers on the network authenticate to Screen Sharing without valid credentials at all. Apple patched this issue with the release of macOS Tahoe 26.6.1, macOS Sequoia 15.7.9, and macOS Sonoma 14.8.9, crediting researcher Alfredo Pesoli (@__rev) at Bynario Atlas (bynar.io) for the discovery. “An attacker on the network may be able to authenticate to Screen Sharing without valid credentials” reads the advisory. According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog. Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure. CISA orders federal agencies to fix the flaws by August 21, 2026 Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, CISA)
We provide guidance for preparing for and mitigating large-scale credential attacks, focusing on recent campaigns targeting security vendors' devices. The post Threat Brief: Mitigating Large-Scale Credential Attacks (Updated August 18) appeared first on Unit 42.
Security controls can block a familiar attack method while missing quieter ways to achieve the same objective. Picus Security's Blue Report 2026 shows how prevention rates can vary dramatically by technique and why behavioral testing is needed to uncover those gaps.
Microsoft says some users are experiencing issues searching in Microsoft 365 apps, including Outlook on the web, Outlook desktop, SharePoint Online, and OneDrive. According to an incident report seen by BleepingComputer and tracked under MO1456424 in the Microsoft 365 Admin Center, the root cause is what Microsoft describes as a recent deployment that causes resource utilization problems. "Impact is specific to some users served through the affected infrastructure who are attempting to search for content in SharePoint Online, OneDrive, Outlook on the web, or Outlook desktop," Microsoft said. "Our investigation identified that a recent deployment introduced a resource utilization inefficiency issue, leading to impact." Microsoft says it has already developed a fix and deployed it to reduce resource pressure and restore service for all affected Microsoft 365 users.
GitLab patched a critical GraphQL flaw that let unauthenticated attackers remotely modify or delete public projects on self-managed servers. GitLab pushed out an emergency patch this week to address a critical flaw, tracked as CVE-2026-19478 (CVSS score of 9.4), that could let an attacker with zero credentials remotely modify or delete public projects and user data. “GitLab has remediated an issue that under certain conditions could allow an unauthenticated user to remotely modify or delete public projects and user data via a GraphQL directive.” reads the advisory. GitLab issued an emergency patch on August 17, five days after its regular update. The vulnerability impacts only self-managed installations, users should upgrade to versions 19.2.4, 19.1.6, 19.0.8, and 18.11.11. There’s a gap worth flagging for anyone still sitting on an older release. The available patches don’t cover the 18.2 through 18.10 branches, even though those versions technically fall inside the affected range. If you’re running anything in that window, staying put isn’t really an option; you’ll need to upgrade to a patched branch entirely rather than waiting for a fix that isn’t coming for your current one. hiimguardian reported the flaw through the company HackerOne bug bounty program. A second, less severe issue shipped in the same release. CVE-2026-19650 (CVSS score of 7.1), involves a cross-site request forgery weakness in how GitLab’s GraphQL handles multiplex queries, letting an unauthenticated attacker trigger mutations through GET requests due to improper validation. Unlike the critical flaw, this one needs a victim to actually interact with something, so it’s a real risk but a considerably narrower one. There’s no evidence either bug has been exploited in the wild yet, and no public proof-of-concept code has surfaced as of publication. That’s the good news. The less comforting part is GitLab’s own disclosure policy: full technical details typically go public on the company’s issue tracker 90 days after the patching release, which puts a working understanding of exactly how this bug functions squarely in mid-November, plenty of time for someone motivated enough to reverse-engineer the patch diff themselves before then. This is not the first serious GitLab issue in recent months. Last month, researchers released working exploit code for another remote-code-execution flaw affecting self-managed servers. Organizations running GitLab on their own infrastructure should therefore treat this patch as a priority, especially given the critical severity and the fact that the vulnerability requires no authentication or user interaction. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, GitLab)
Microsoft announced that it removed the Windows Management Instrumentation Command-line (WMIC) tool from Windows 11 24H2 and 25H2, as well as from Windows 11 beta builds released this week. WMIC is a legacy built-in Windows command-line utility that helps interact with the Windows Management Instrumentation (WMI) system using text commands. This move is part of a process announced in September, when the company said that WMIC will be removed after upgrading to Windows 11 25H2 and later. Microsoft deprecated WMIC in Windows Server 2012 (in 2016) and Windows 10 21H1 (in 2021), and it converted it into a Feature on Demand (FoD) starting with Windows 11 22H2 (in 2022), and announced in January 2024 that it would be removed altogether after first disabling it by default. "Windows Management Instrumentation Command-line (WMIC) has been removed in this release. This change is part of the ongoing deprecation and removal of WMIC from Windows," Microsoft noted on Monday.
Varonis Threat Labs has disclosed three vulnerabilities in Microsoft Copilot Personal that it said could allow a single click on a crafted link to silently pull data from connected apps and other information available to the victim's Copilot session. The flaws, which the researchers collectively named CoSnitch, turn in part on an undocumented URL parameter that the assistant itself surfaced
Security researchers at Anthropic and Switzerland's EPFL have demonstrated that self-propagating payloads can spread from one artificial intelligence (AI) agent to the next through the editable system prompt files that autonomous agent harnesses use to carry state between sessions. The work, released as a preprint on August 10, 2026, tests the technique in a simulated six-agent coding
Cybersecurity researchers have disclosed details of a previously undocumented Python implant framework dubbed TWINLOOT. "TWINLOOT is a modular, PyArmor-hardened Python implant designed to operate its entire command-and-control infrastructure inside trusted Microsoft services," Ontinue said in a technical report shared with The Hacker News. "Tasking flows through SharePoint Online file
Cybersecurity researchers have flagged a new typosquatting campaign targeting RubyGems users with a Windows-based information stealer. OpenSourceMalware, which discovered the activity on August 15, 2026, is tracking the threat under the moniker StubMaker. The complete list of packages published as part of the campaign is below - ubnuler ubnlder ri18nr reaker rakier orakw joxn
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