CVE-2026-48135: Check Point HTTP Service DoS Vulnerability

CVE-2026-48135 Overview

CVE-2026-48135 affects a Check Point HTTP-based service that incorrectly handles malformed HTTP requests. The flaw resides in the HTTP request parsing and validation logic, allowing a remote attacker to send crafted requests that disrupt service availability. The vulnerability is classified under [CWE-122] (Heap-based Buffer Overflow), indicating that malformed input can corrupt heap memory during request processing. No authentication or user interaction is required to reach the vulnerable code path, and the service is exposed over the network.

Critical Impact

Remote unauthenticated attackers can send malformed HTTP requests to trigger a limited availability impact on the affected Check Point HTTP service.

Affected Products

• Check Point HTTP-based service (specific product version not enumerated in NVD data)
• See the Check Point Security Advisory sk184991 for the authoritative list of affected versions
• Vendor-confirmed scope is published only through Check Point's support portal

Discovery Timeline

• 2026-05-26 - CVE-2026-48135 published to NVD
• 2026-05-26 - Last updated in NVD database

Technical Details for CVE-2026-48135

Vulnerability Analysis

The vulnerability stems from improper handling of malformed HTTP requests within a Check Point HTTP-based service. According to the NVD description, the request parsing and validation layer fails to safely process inputs that deviate from expected HTTP grammar. Combined with the [CWE-122] classification, this indicates that malformed requests can cause heap memory to be written or read outside intended boundaries during parsing.

The attack surface is reachable over the network without credentials. The integrity and confidentiality impact is none, while the availability impact is low, consistent with a service crash or degraded responsiveness rather than full code execution. Successful exploitation interrupts the HTTP-based service, which in Check Point gateways may include management or web-based access components.

Root Cause

The root cause is insufficient validation of HTTP request structures before they are processed by heap-allocated buffers. When the service encounters request elements that violate length, encoding, or structural assumptions, the parser writes or reads outside the bounds of an allocated heap region. This pattern matches the [CWE-122] heap buffer overflow weakness.

Attack Vector

An attacker sends a specially crafted HTTP request over the network to the exposed Check Point HTTP service endpoint. The request includes malformed fields, oversized headers, or protocol-violating constructs that the parser fails to reject early. Processing the request corrupts the heap layout, terminating the service worker or stalling request handling.

No verified exploit code is publicly available, and the vulnerability is not listed in the CISA KEV catalog. The EPSS data indicates a low predicted probability of exploitation in the near term. Refer to the Check Point Security Advisory sk184991 for vendor technical details.

Detection Methods for CVE-2026-48135

Indicators of Compromise

• Unexpected restarts or crashes of the Check Point HTTP-based service process
• Spikes in HTTP 400 and malformed request errors in gateway logs
• Inbound HTTP requests with oversized headers, invalid chunked encoding, or non-RFC-compliant request lines
• Repeated connections from the same source immediately preceding service degradation

Detection Strategies

• Inspect HTTP traffic destined for Check Point management and web services for protocol violations and abnormally large header fields
• Correlate service crash events on the gateway with inbound network traffic from external sources
• Enable verbose logging on the HTTP-based service to capture parser errors and malformed request markers

Monitoring Recommendations

• Forward Check Point gateway logs to a centralized analytics platform and alert on service restart patterns
• Baseline normal HTTP request characteristics, and alert on deviations such as header size outliers
• Monitor exposure of the management HTTP service to untrusted networks and alert on unauthorized reachability

How to Mitigate CVE-2026-48135

Immediate Actions Required

• Review the Check Point Security Advisory sk184991 and identify affected versions in your environment
• Restrict network access to the Check Point HTTP-based service so that only trusted management networks can reach it
• Apply vendor-provided hotfixes or upgrades as soon as they are validated in a test environment

Patch Information

Check Point publishes remediation guidance and fixed versions through advisory sk184991. Administrators should consult that advisory for the specific JHF, hotfix, or version upgrade applicable to their deployed gateway and management server builds.

Workarounds

• Place the management HTTP service behind a VPN or jump host so that it is not exposed to the public internet
• Use access control lists to restrict source IP addresses permitted to reach the HTTP-based service
• Deploy an upstream reverse proxy or WAF that enforces strict HTTP request validation before traffic reaches the Check Point service

# Configuration example: restrict management HTTP access using GAiA CLI
# Replace the placeholder network with your trusted management subnet
set web ssl-port 443
add allowed-client host ipv4-address 10.0.0.0 mask-length 24
save config