Schedule Posts CalendarWordPress extension · Toolstack
CVE-2023-40556
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedCross-Site Request Forgery (CSRF) vulnerability in Greg Ross Schedule Posts Calendar plugin <= 5.2 versions.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceCross-Site Request Forgery (CSRF) vulnerability exists in the Schedule Posts Calendar WordPress plugin by Greg Ross affecting versions up to and including 5.2. The vulnerability allows attackers to induce authenticated users to perform unintended state-changing actions via maliciously crafted requests.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Schedule Posts CalendarWordPress extension
<= 5.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check the installed version of Schedule Posts Calendar pluginNavigate to WordPress admin dashboard > Plugins > Installed Plugins, find 'Schedule Posts Calendar' by Greg Ross, and note the version number displayed. Alternatively, check the plugin's main PHP file (schedule-posts-calendar.php) for the 'Version' header comment.Affected if Version is 5.2 or lower
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Inspect plugin code for nonce implementationExamine the plugin's PHP files for state-changing operations (forms, AJAX calls, URL parameters that modify data). Look for calls to wp_verify_nonce(), check_ajax_referer(), or wp_create_nonce() functions.Affected if State-changing functions lack nonce verification (wp_verify_nonce or check_ajax_referer calls are missing or improperly implemented)
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Verify nonce field usage in formsInspect any HTML forms in the plugin that perform state-changing actions (creating, editing, or deleting posts/schedules). Check if forms include nonce fields using wp_nonce_field() or similar functions.Affected if Forms performing state changes do not include hidden nonce fields
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Check AJAX handlers for referer verificationReview the plugin's AJAX action handlers (admin-ajax.php or REST API endpoints). Determine if they verify the request origin using check_ajax_referer() or manually validate the referer header.Affected if AJAX handlers do not verify request origin or nonce
You are affected if the Schedule Posts Calendar plugin version is 5.2 or earlier AND the plugin's state-changing operations lack proper CSRF token (nonce) validation.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade the Schedule Posts Calendar plugin to version 5.3 or later. Additionally, implement proper CSRF tokens (nonces) on all state-changing operations and verify Origin/Referer headers to prevent cross-site request forgery attacks.
Fix this in Schedule Posts Calendar
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-40556 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-40556 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data