Atomicorp WAF Rule 314150

Rule Summary

• Rule ID: 314150
• Status: Active
• Alert message: Atomicorp.com WAF Rules: Oversized POST argument name (PHP OOM corruption CVE-2026-109618)
• Observed CWEs: CWE-79 (1), CWE-90 (1), CWE-269 (1), CWE-521 (1), CWE-732 (1)
• Revision: 1
• Rule severity: Critical (2)
• Phase: 2 (request body)
• Rule action: deny
• HTTP status: 403
• Public tags: cve/CVE-2026-109618
• Logging: log, auditlog

Description

This rule detects behavior identified by its current alert as “Oversized POST argument name (PHP OOM corruption CVE-2026-109618)”. It evaluates during the request body phase and denies matching traffic with HTTP status 403.

CVEs Referenced by This Rule

The current ModSecurity rule metadata explicitly names the following CVEs. These references explain the rule author’s association; they do not claim that the rule is limited to these vulnerabilities or that this is an exhaustive coverage list.

CVE-2026-109618

PHP uses longjmp() for out-of-memory (OOM) errors to exit the current context and abort handling of the request. Some contexts may not properly account for this scenario and leave request memory in an uninitialized state before performing an allocation. The subsequent request cleanup procedure may read or branch on this memory. Multiple OOM strategies can consistently trigger this condition and lead to remote code execution (RCE).

• Association: The rule references CVE-2026-109618 in its alert message and tag.
• CVE Record (opens in a new tab)
• NVD (opens in a new tab)

Selected Related CVEs

This is a selected list of documented research observations, not an exhaustive coverage matrix. Absence of a CVE does not imply absence of protection.

Observed CWEs

These CWEs are recorded on published CVEs in the selected observations associated with this rule. They are observational relationships, not a claim that the rule universally blocks every vulnerability assigned to a CWE.