VulnCheck reports that attackers are actively exploiting an unpatched flaw in Langflow, a popular open-source platform for building AI applications. The bug (CVE-2026-5027, rated 8.8) is a path-traversal weakness: the file-upload endpoint does not clean the supplied filename, so an attacker can use directory-climbing sequences to write files anywhere on the server, a foothold that leads to remote code execution. Tenable, which found it, says the maintainers did not respond after three contact attempts in early 2026, and there is still no official fix. Early exploitation appears to be probing, with attackers writing harmless test files, but that usually precedes heavier attacks.
Microsoft has shipped the first full patch for an Exchange Server zero-day that attackers have been exploiting since May. The flaw (CVE-2026-42897) is a cross-site scripting bug in Outlook Web Access: an attacker emails a victim, and when the message is opened in OWA, malicious JavaScript runs inside the victim's authenticated session, allowing session-token theft and mailbox impersonation without ever touching the server. It affects Exchange Server 2016, 2019, and Subscription Edition, and CISA added it to its known-exploited list back in May. Until this week only temporary mitigations existed; the June security updates provide the permanent fix.
Ivanti has patched two critical flaws in Sentry, its mobile gateway appliance (formerly MobileIron Sentry) that sits in line between mobile devices and back-end systems like Exchange. The worst, CVE-2026-10520, rated a perfect 10, is an OS command injection in an internal configuration API that mistakenly accepts commands from anyone who can reach it over the internet, with no login, granting remote code execution as root. The second, CVE-2026-10523 (9.9), is an authentication bypass that lets attackers create their own admin accounts. No exploitation has been seen yet, but watchTowr has already published a patch analysis and a detection script, so the window is closing fast.
Researchers at Cyera have disclosed six vulnerabilities, collectively named Proto6, in protobuf.js, a JavaScript and TypeScript library for Google's Protocol Buffers data format that sees more than 50 million downloads a week. The flaws stem from the library trusting schema and metadata by default, so a single malicious schema or crafted payload can crash a service, inject code, or lead to remote code execution. Cyera demonstrated real attacks including poisoning CI/CD pipelines to leak build secrets and crashing WhatsApp automation bots. Because protobuf.js is embedded across cloud services, AI platforms, and build systems, the reach is broad. Fixed versions are 7.5.6 and 8.0.2.
Microsoft's June 2026 Patch Tuesday is the largest on record, fixing more than 200 vulnerabilities (independent counts put the total above 206), including three publicly disclosed zero-days that are not yet being exploited. The standout is CVE-2026-45586, a Windows CTFMON elevation-of-privilege flaw that grants SYSTEM access, which matches the GreenPlasma bug a researcher dropped in protest of Microsoft's bug-bounty handling; a BitLocker bypass called YellowKey was also fixed. The update includes 33 critical flaws, most of them remote code execution, hitting Remote Desktop, Hyper-V, Office, and cryptographic services. Microsoft flagged 15 issues as more likely to be exploited soon.
Hours after Patch Tuesday, the researcher known as Nightmare Eclipse published a working exploit, dubbed RoguePlanet, for an unpatched Microsoft Defender flaw that opens a command prompt with full SYSTEM privileges on fully updated Windows 10 and 11. The bug is a race condition, so the exploit is hit or miss, but the researcher reports a 100 percent success rate on some machines. They posted the proof-of-concept on a self-hosted Git server after Microsoft had earlier taken down their GitHub and GitLab repositories. It is the latest in a string of Windows zero-days (BlueHammer, RedSun, YellowKey, GreenPlasma) the researcher has released in protest of Microsoft's disclosure practices.
Google has shipped an emergency Chrome fix for a zero-day in V8, the browser's JavaScript and WebAssembly engine, that attackers are already exploiting in the wild. The flaw (CVE-2026-11645, rated 8.8) is an out-of-bounds memory read and write that lets a malicious web page run code inside Chrome's sandbox, and can help defeat protections like ASLR to set up a fuller compromise. Google confirmed an exploit exists but withheld details until most users update. It is the fifth actively exploited Chrome zero-day of 2026. The fix is in Chrome 149.0.7827.102/103 for desktop; Chromium-based browsers like Edge and Brave need the same update.
Attackers are actively exploiting a flaw in LiteLLM, a widely used open-source gateway that routes requests to AI models, and CISA has added it to its known-exploited-vulnerabilities list. The bug (CVE-2026-42271) lets any authenticated user run commands on the host through test endpoints that spawn whatever command is supplied in the request. Chained with a separate Host-header bypass in the Starlette web framework (CVE-2026-48710), it becomes unauthenticated remote code execution, giving full control of the server, credential theft, and a foothold in connected AI infrastructure. Horizon3.ai has published a proof-of-concept. It follows a LiteLLM SQL injection flaw exploited within 36 hours last month.
Veeam has patched a critical flaw in Backup and Replication, one of the most widely deployed enterprise backup tools, that lets any authenticated low-privilege domain user run code remotely on the backup server. The bug (CVE-2026-44963, rated 9.4) only affects version 12 installations joined to an Active Directory domain; version 13, which uses a different architecture, is not affected, and workgroup setups are safe. No exploitation has been seen yet, but Veeam warns attackers often move quickly once patches reveal the flaw, and backup servers are a prime ransomware target because compromising them cripples recovery. The fix is build 12.3.2.4854.
Check Point has rushed out a fix for a critical flaw in its Remote Access VPN, Mobile Access, and Spark firewall products that attackers have been exploiting since May 7. The bug (CVE-2026-50751, rated 9.3) is a logic error in how the software checks certificates, letting an unauthenticated attacker log into the VPN with no password, but only on gateways still using the old IKEv1 key-exchange protocol. So far a few dozen organizations have been hit, and at least one intrusion was tied to an affiliate of the Qilin ransomware gang, which used the access to steal data with Rclone before deploying ransomware. A second, unexploited flaw was also patched.