CVE-2025-43840Network attack vector

Stored XSS via missing nonce validation

Published May 19, 2025 · Updated Apr 28, 2026

Cross-site request forgery in ref CheckBot 1.05 and earlier allows remote attackers to inject stored scripts through forged requests. An undisclosed settings-update function accepts a forged administrative request because nonce validation is missing or incorrect. Exploitation requires tricking a site administrator into acting on a malicious link, after which the injected script executes for visitors to the affected WordPress page.

CVSS severity7.1
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in ref CheckBot 1.05 and earlier allows remote attackers to inject stored scripts through forged requests. An undisclosed settings-update function accepts a forged administrative request because nonce validation is missing or incorrect. Exploitation requires tricking a site administrator into acting on a malicious link, after which the injected script executes for visitors to the affected WordPress page.

The record

CVE
CVE-2025-43840
Published
May 19, 2025
Updated
Apr 28, 2026
Vendor
ref
Product
CheckBot
Classifications
CWE-352, CAPEC-592, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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 <=1.05

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ref · CheckBotversion=0 <=1.05

Published CVSS scores

7.1PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
CAPEC-592Stored XSS
T1203Exploitation for Client Execution

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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