CVE-2026-73252
Description
A flaw was found in Mongoose. An unauthenticated remote attacker can cause a Denial of Service (DoS) by sending a specially crafted Transport Layer Security (TLS) record to an affected server. Due to improper message length validation in the built-in TLS implementation, processing the malformed record triggers an integer underflow and an out-of-bounds memory read, causing the application to crash.
Statement
This vulnerability is rated as Important because an unauthenticated remote attacker across the network can force a service crash prior to session authentication, causing an immediate denial of service. The rating remains Important rather than Critical as the flaw does not facilitate arbitrary code execution or data exposure. In Red Hat environments, enterprise products are not affected as Mongoose is not included in Red Hat Enterprise Linux. Additionally, triggering the flaw requires an application to be compiled using the internal TLS implementation instead of standard system cryptographic libraries.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
