CyberSecBulletin
CVE-2026-85103NVD status: Awaiting Analysis

Quantum Security Gateway: Heap-based Buffer Overflow

CVE-2026-85103 is a critical-severity heap-based buffer overflow vulnerability in Quantum Security Gateway from Check Point, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Quantum Security Gateway versions: R82.10 with Jumbo Hotfix Take 43 or below; R82 with Jumbo Hotfix Take 125 or below; R81.20 with Jumbo Hotfix Take 165 or below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 4.29% chance of exploitation within 30 days, which is in the top 8.73% of all scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Quantum Security Gateway you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Check PointQuantum Security GatewayR82.10 with Jumbo Hotfix Take 43 or below; R82 with Jumbo Hotfix Take 125 or below; R81.20 with Jumbo Hotfix Take 165 or belowNot stated
Check PointQuantum Security ManagementR82.10 with Jumbo Hotfix Take 43 or below; R82 with Jumbo Hotfix Take 125 or below; R81.20 with Jumbo Hotfix Take 165 or belowNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (checkpoint.com).

Official description

A heap-based buffer overflow in VPN certificate ASN.1 decoding may allow an unauthenticated remote attacker to execute arbitrary code on Check Point Quantum Security Management and Quantum Security Gateway systems.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Heap-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the heap.

How developers prevent this class of flaw

  • Pre-design: Use a language or compiler that performs automatic bounds checking.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Heap-based Buffer Overflow vulnerabilities (CWE-122)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Quantum Security Gateway

All Quantum Security Gateway vulnerabilities

Recent Heap-based Buffer Overflow vulnerabilities

Spotted an error? Tell us.