ZeroHour

CVE-2026-91843

Unauthenticated stack overflow gives root RCE in Check Point login process

CVSS 3.1
9.8 critical
EPSS
Published
()
Modified
AI analysis

CVE-2026-91843 is a stack-based buffer overflow (CWE-121) in the unauthenticated login process of a Check Point product, as Check Point Software ([email protected]) is the assigning CNA and its CVE scope covers Check Point products. An attacker can trigger the flaw remotely by sending crafted input to the login interface before authenticating, with no user interaction or credentials required. Successful exploitation allows arbitrary code execution with root privileges, the highest level of control on the affected system. The vulnerability is rated 9.8 Critical (AV:N/AC:L/PR:N/UI:N, all impacts high), reflecting trivial network exploitability. No public proof-of-concept or confirmed in-the-wild exploitation is known at this time, and the source data does not name the specific product line or affected version ranges.

What to do: Monitor Check Point's official advisory channels for the affected product/version list and patch release, and upgrade as soon as fixed versions are published. In the interim, restrict the login/management interface of Check Point appliances to trusted management networks and remove any direct internet exposure, and review perimeter logs for anomalous pre-authentication traffic against that interface.

Affected
Check Point
Estimated exposure
No basis for an estimate.

Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.

Description

A stack overflow during the unauthenticated login process may allow an attacker to run arbitrary code remotely with root privileges.

Weakness
CWE-121
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

In the news

Check Point Vulnerability Lets Remote Hackers Gain Root Access Without Authentication

Check Point patched CVE-2026-91843, a CVSS 9.8 pre-auth stack overflow granting remote root on Security Management and Log Servers.

Check Point released an urgent fix for CVE-2026-91843 (CVSS 3.1: 9.8), a stack-based buffer overflow triggered by an excessively long username during login that lets an unauthenticated remote attacker execute arbitrary code with root privileges. Affected products include Security Management Server, Multi-Domain Security Management Server, and Log Servers across releases from R80 through R82.20, with fixes delivered via LivePatch and urgent Take packages. The vendor reports no observed exploitation in the wild, and administrators are advised to verify patch deployment and restrict SmartConsole Trusted Clients.