Really Simple Security (Free) < 9.8.3 - Unauthenticated Unbounded Option Growth via Spoofed Client IP Header (CVE-2026-88798) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-88798

Really Simple Security (Free) < 9.8.3 - Unauthenticated Unbounded Option Growth via Spoofed Client IP Header

Answer in brief

CVE-2026-88798 records a Unknown severity vulnerability in Really Simple Security (Free) < 9.8.3 - Unauthenticated Unbounded Option Growth via Spoofed Client IP Header. The current sources do not mark it as known exploited. The current feed maps Unknown/Really Simple Security (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 18, 2026Updated Sep 18, 2026Source checked Sep 18, 2026First seen by HOL Sep 18, 2026Material review Sep 18, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Unknown/Really Simple Security (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Unknown/Really Simple Securitygeneric	>=8.1.6 <9.8.3	9.8.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for Unknown/Really Simple Security.
Review the reported fix. Update Unknown/Really Simple Security to 9.8.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 18, 2026

Sources and claim methodology

Source referencewpscan.com

Upstream source description

The Really Simple Security WordPress plugin before 9.8.3 does not validate a client-supplied address value before using it as a storage key in one of its own options, allowing unauthenticated attackers to grow that option without bound and to slow the site's handling of missing pages.

Quoted source text, attributed separately from HOL analysis.