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Atomicorp WAF Rule 314149

Rule Summary

  • Rule ID: 314149
  • Status: Active
  • Alert message: Atomicorp.com WAF Rules: tripwire: oversized PHPSESSID response cookie (possible PHP memory disclosure CVE-2026-109618)
  • Observed CWEs: None documented
  • Revision: 1
  • Rule severity: Critical (2)
  • Phase: 5 (logging)
  • Request surfaces: Response headers
  • Rule action: pass
  • Public tags: cve/CVE-2026-109618, no_ar
  • Logging: log, auditlog

Description

This rule detects behavior identified by its current alert as “tripwire: oversized PHPSESSID response cookie (possible PHP memory disclosure CVE-2026-109618)” in the response headers. It evaluates during the logging phase and records the match without a disruptive action.

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).

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

No selected related public CVE research notes are currently published.