CVE-2026-81766Network attack vectorHinoki check available

Subsite-admin code execution via unchecked plugin installation

Published Aug 30, 2026 · Updated Aug 30, 2026

Improper authorization in Really Simple Security before 9.8.0 allows remote authenticated users to execute code through plugin installation. The rsp_upgrade_install_plugin handler accepts a user-supplied package URL and writes its code into the network-shared plugin directory without checking network-level installation authority. Exploitation requires a multisite subsite administrator and a non-default setting that exposes the plugin administration menu to subsites.

CVSS severityUnavailable
Unscored
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper authorization in Really Simple Security before 9.8.0 allows remote authenticated users to execute code through plugin installation. The rsp_upgrade_install_plugin handler accepts a user-supplied package URL and writes its code into the network-shared plugin directory without checking network-level installation authority. Exploitation requires a multisite subsite administrator and a non-default setting that exposes the plugin administration menu to subsites.

The record

CVE
CVE-2026-81766
Published
Aug 30, 2026
Updated
Aug 30, 2026
Vendor
Really Simple Plugins
Product
Really Simple Security
Classifications
CWE-269, T1068
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <9.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Really Simple Plugins · Really Simple Securityversion=0 <9.8.0

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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