CVE-2026-6551
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 · uneditedThe Timeline Blocks for Gutenberg plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'titleTag' attribute of the timeline-blocks/tb-timeline-blocks block in all versions up to, and including, 1.1.10 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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 · high confidenceThe Timeline Blocks for Gutenberg WordPress plugin versions up to 1.1.10 are vulnerable to stored XSS via the 'titleTag' attribute of the timeline-blocks/tb-timeline-blocks block. Authenticated attackers with contributor-level access can inject arbitrary JavaScript through insufficiently sanitized input that is not properly escaped on output.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
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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Confirm Timeline Blocks plugin is installedNavigate to WordPress admin > Plugins and look for 'Timeline Blocks for Gutenberg' in the installed plugins list; or check the /wp-content/plugins/ directory for a folder named 'timeline-blocks' or similarAffected if The plugin is installed and active in WordPress
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Identify installed plugin versionIn Plugins admin page, click the plugin name to view details, or inspect the plugin's main PHP file header for the 'Version' comment, or check /wp-content/plugins/timeline-blocks/timeline-blocks.phpAffected if Version is 1.1.10 or lower
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Check for use of tb-timeline-blocks blockOpen the WordPress block editor (Gutenberg) and search for 'Timeline' in the block inserter, or query the WordPress database: SELECT * FROM wp_posts WHERE post_content LIKE '%tb-timeline-blocks%'Affected if Any posts/pages contain the timeline-blocks/tb-timeline-blocks block
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Inspect titleTag attribute in existing timeline blocksQuery post content for titleTag values: SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%titleTag%', then examine the raw block JSON in post_content to find titleTag values; look for any injected script tags or event handlersAffected if Any titleTag attribute contains unsanitized HTML, script tags, or javascript: URIs
User is affected if Timeline Blocks for Gutenberg plugin version 1.1.10 or lower is installed AND the tb-timeline-blocks block is in use with a potentially malicious titleTag value present in post content.
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 to version 1.1.11 or later to obtain patched code with proper input sanitization and output escaping; audit existing timeline block content for any injected scripts.
- Consultation2.0 h
- Implementation2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-6551 — 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-2026-6551 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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- 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