.NET December 2025 Servicing Updates Released

Critical n8n Flaw Exposes 100k Servers: Full Takeover via Unauthenticated Access + Video Introduction: A critical vulnerability (CVE-2026-21858, CVSS 10.0) has been uncovered in the popular workflow automation platform n8n, putting an estimated 100,000 servers at risk of complete compromise. This flaw allows unauthenticated attackers to read local files, including configuration files containing the encryption key for all stored credentials. As demonstrated by security researchers, possessing this key enables the decryption of sensitive credentials, leading to a full chain of attack from initial access to total system takeover....

Microsoft has confirmed that the December 2025 security updates are breaking Message Queuing (MSMQ) functionality, affecting enterprise applications and Internet Information Services (IIS) websites.

Microsoft has confirmed that the December 2025 security updates are breaking Message Queuing (MSMQ) functionality, affecting enterprise applications and Internet Information Services (IIS) websites.

Microsoft releases critical mitigations for React2Shell vulnerability (CVE-2025-55182) affecting React Server Components. Immediate patching and input validation recommended. Link: https://lnkd.in/eh4ffbAj #Security #Vulnerability #Patching #Validation #CVE #React #Components #Mitigations #Threat #Protection #Update #Software #Tech #Microsoft #Fix #Safety #Bug #Alert #Critical #Server

🚨 High risk vulnerability detected in Microsoft ASP.NET! Remote attackers can execute arbitrary code due to improper access control within SOAP web service definitions. This highlights the importance of API security. Stay safe! #Microsoft #ASP.NET #Vulnerability #OWASP #APIsecurity https://lnkd.in/gqmfwjXE

Critical IDOR Flaw Exposes Servers: How a Single Parameter Can Lead to Full Infrastructure Compromise + Video Introduction: Insecure Direct Object References (IDOR) remain one of the most dangerous and prevalent authorization flaws in web applications. A recent critical finding, as detailed by a security researcher, demonstrates how a single unprotected `server_ids` parameter in a server management platform allowed authenticated attackers to seize administrative control of any remote server, bypassing all tenant isolation. This incident underscores the catastrophic consequences of misplaced trust in client-side controls and the absolute necessity of rigorous server-side authorization logic....

Microsoft has confirmed that the December 2025 security updates are breaking Message Queuing (MSMQ) functionality, affecting enterprise applications and Internet Information Services (IIS) websites. [...] #Microsoft

MongoBleed (CVE-2025-14847) is a serious memory leak vulnerability where the server accidentally sends back the entire allocated memory buffer instead of just the actual decompressed data. Because of this, an unauthenticated attacker can send a very small request and receive a huge response filled with whatever sensitive information happened to be in the server’s RAM at that time, things like AWS access keys, passwords, or admin credentials. The scary part is that attackers don’t need to log in at all. They can completely bypass authentication, steal high privilege credentials, and potentially take over the entire infrastructure. Around 87,000 servers are currently exposed. Fix immediately by applying the official patch or, if that’s not possible right away, disable zlib compression as a temporary mitigation.

Microsoft reports 7.8-rated zero day, plus 56 more in December Patch Tuesday To exploit this bug, an attacker must already have code execution rights on the targeted system, but assuming they've already achieved this, they can then abuse CVE-2025-62221 to escalate privileges and gain system-level access. So prioritize patching this one first. https://nuel.ink/7AJHBg

A severe vulnerability known as Ni8mare (CVE-2026-21858) allows remote attackers to take control of n8n servers, affecting over 100,000 instances. Discovered by Cyera, this flaw has a perfect severity score of 10 out of 10 and can expose sensitive information. n8n, an open-source workflow automation platform, is widely used for integrating applications and automating tasks, making this vulnerability particularly concerning for organizations relying on it. https://lnkd.in/grvD6Bkv