CVE-2026-54219
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 · uneditedUBB.threads is vulnerable to Stored XSS via user posts and user profile fields. The application fails to properly sanitize user input, allowing low privileged attackers to inject arbitrary JavaScript that executes in a victim's browser upon viewing. Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 7.7.5 but may also affect other 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 confidenceUBB.threads 7.7.5 contains a stored Cross-Site Scripting (XSS) vulnerability in user posts and user profile fields. The application fails to properly sanitize user-supplied input before rendering it in HTML contexts, allowing authenticated low-privilege users to inject malicious JavaScript payloads that execute in the browsers of other users who view the affected content.
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
- Authentication
- X
- User interaction
- P
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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 UBB.threads installation versionLocate the version file or admin panel that displays the UBB.threads version number. Common locations include the admin dashboard, a version.php file in the installation root, or the footer of the web interface.Affected if The installed version is exactly 7.7.5 or falls within any other affected version range if subsequently disclosed.
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Verify user posting feature is enabledCheck the UBB.threads admin panel under General Settings or Permissions to confirm whether registered users (including low-privilege users) can create posts or edit their profile fields.Affected if User-generated content features are enabled and accessible to authenticated users.
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Inspect post rendering code for sanitizationExamine the PHP files responsible for displaying user posts, typically found in the /scripts or /includes directories. Look for functions that handle output of post content (such as post_display, format_post, or similar display functions).Affected if No output encoding, htmlspecialchars, or XSS sanitization is applied to user post content before rendering to HTML.
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Inspect profile field rendering code for sanitizationExamine the PHP files that render user profile fields in the profile display pages. Check the code that outputs profile data (such as profile.php or userinfo.php).Affected if No output encoding or input sanitization is applied to profile field values before they are rendered in the browser.
You are affected if UBB.threads version 7.7.5 is installed, user posting or profile editing is enabled, and the codebase lacks proper output encoding on user-generated content before HTML rendering.
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 dataImplement context-aware output encoding and input validation for all user-generated content including posts and profile fields. Until an official vendor patch is available, consider deploying a WAF rule to detect and block XSS attack patterns in HTTP parameters.
- Consultation4.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-54219 — 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-2026-54219 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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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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