CVE-2026-92853
8.7HighPublished 20 Oct 2026 · NVD status: Received · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- High impact on availability
- Weakness
- CWE-125, CWE-191
Impact
Remote unauthenticated attackers can crash the service by sending a malformed four-byte TLS 1.3 handshake header, causing a denial of service. No credentials, cryptographic validity, or user interaction are required.
Root cause
The TLS 1.3 Certificate message parser decrements the message length to skip a context byte without checking for available data, causing an unsigned integer underflow to 0xFFFFFFFF and an out-of-bounds read past the buffer.
Affected systems
Versions not listed — check the vendor advisory.
CVSS v4.0 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Fix & remediation
Upgrade NetX Secure / NetXDuo to the patched release referenced in advisory GHSA-893m-9g4r-4992 once available, or disable TLS 1.3 support if patching cannot be done immediately.
AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
The TLS 1.3 Certificate-message parser in NetX Secure decrements the message length to skip a context byte without first establishing that the message has a byte to skip. A zero-length Certificate message therefore wraps the unsigned length to `0xFFFFFFFF`, which makes the bounds check that follows vacuous and sends the parser reading past the session packet buffer. The trigger is a four-byte handshake header and requires no cryptographic validity. It is reachable pre-authentication.