CVE-2026-26333 Calero VeraSMART < 2022 R1 .NET Remoting Arbitrary File Read Leading to ViewState RCE
Unauthenticated attackers can exploit exposed .NET Remoting endpoints to read sensitive files and achieve remote code execution via ViewState deserialization.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-26333?
CVE-2026-26333 is a critical unsafe deserialization vulnerability in Calero VeraSMART, published on 13 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Calero VeraSMART versions prior to 2022 R1 expose an unauthenticated .NET Remoting HTTP service on TCP port 8001. The service publishes default ObjectURIs (including EndeavorServer.rem and RemoteFileReceiver.rem) and permits the use of SOAP and binary formatters with TypeFilterLevel set to Full. An unauthenticated remote attacker can invoke the exposed remoting endpoints to perform arbitrary file read and write operations via the WebClient class. This allows retrieval of sensitive files such as WebRoot\\web.config, which may disclose IIS machineKey validation and decryption keys. An attacker can use these keys to generate a malicious ASP.NET ViewState payload and achieve remote code execution within the IIS application context. Additionally, supplying a UNC path can trigger outbound SMB authentication from the service account, potentially exposing NTLMv2 hashes for relay or offline cracking.
Which versions are affected by CVE-2026-26333?
It affects 1 product.
Products include Calero Verasmart.
How do I fix CVE-2026-26333?
No fix has been published for CVE-2026-26333 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-26333 being exploited?
There is no known exploitation of CVE-2026-26333 in the wild and no public exploit code.
Other vulnerabilities in Calero VeraSMART
Sources
Also known as GHSA-m4w4-g5c5-j4f4.