CVE-2026-16775 is a stored XSS in the Smash Balloon Social Photo Feed plugin (versions through 4.9.0), affecting the 'id' shortcode attribute. The CVSS 6.4 (medium) rating reflects a contributor-level access prerequisite, but the EPSS probability of 0.00193 is conspicuously low — and that gap is the actual analytical puzzle, not the severity score itself. The contributor barrier is real but overrated as a defensive moat: these accounts target editorial staff who are routinely phished, subjected to credential stuffing, or compromised through supply-chain attacks on other plugins. A single compromised contributor can inject persistent scripts into every page rendering that shortcode — and Smash Balloon's social feed shortcodes typically appear on public-facing, high-traffic pages designed for visitor engagement. The EPSS likely measures current attacker awareness, not inherent difficulty. Smash Balloon has had prior CVEs, placing it in existing enumeration tooling. The specific 'id' shortcode attribute is obscure enough that no reliable PoC has circulated yet — but the WordPress plugin ecosystem has a documented pattern where obscure attack surfaces stay low-EPSS only until a researcher bothers to map them. The disclosed-but-unfixed window is the danger phase: auto-update adoption in the WordPress plugin ecosystem is structurally low, meaning many sites running this plugin will remain vulnerable for weeks or months after a patch exists. Treat this as a priority patch regardless of the EPSS number — the low score reflects market inefficiency, not your actual exposure. Verify your installed version, check for contributor-level accounts you didn't provision, and monitor your site for unusual shortcode configurations in post content.
CVE-2026-16775
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 Smash Balloon Social Post Feed – Simple Social Feeds for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'id' Shortcode Attribute in all versions up to, and including, 4.9.0 due to insufficient input sanitization and output escaping. 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 analysisUntrusted input is placed into a web page without being neutralised, so an attacker's markup or script executes in another user's browser. That can hijack sessions, capture keystrokes, or silently perform actions as the victim. Fixing it properly means context-aware output encoding everywhere data meets HTML, backed by a content-security policy as a second line of defence.
General guidance for the cross-site scripting (xss) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
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
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 dataThere is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.
Free. We build fixes in the order the community asks for them — and we’ll tell you the moment this one lands.
We develop and verify an original fix where the vendor hasn’t, from $2,200. Deployed to your staging first — never straight to production.
Scope it with usSee what else the community needs solved on the solutions-needed board.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-16775 — 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 sourcesCVE-2026-16775 is a stored XSS in the Smash Balloon Social Photo Feed plugin (versions through 4.9.0), affecting the 'id' shortcode attribute. The CVSS 6.4 (medium) rating reflects a contributor-level access prerequisite, but the EPSS probability of 0.00193 is conspicuously low — and that gap is the actual analytical puzzle, not the severity score itself. The contributor barrier is real but overrated as a defensive moat: these accounts target editorial staff who are routinely phished, subjected to credential stuffing, or compromised through supply-chain attacks on other plugins. A single compromised contributor can inject persistent scripts into every page rendering that shortcode — and Smash Balloon's social feed shortcodes typically appear on public-facing, high-traffic pages designed for visitor engagement. The EPSS likely measures current attacker awareness, not inherent difficulty. Smash Balloon has had prior CVEs, placing it in existing enumeration tooling. The specific 'id' shortcode attribute is obscure enough that no reliable PoC has circulated yet — but the WordPress plugin ecosystem has a documented pattern where obscure attack surfaces stay low-EPSS only until a researcher bothers to map them. The disclosed-but-unfixed window is the danger phase: auto-update adoption in the WordPress plugin ecosystem is structurally low, meaning many sites running this plugin will remain vulnerable for weeks or months after a patch exists. Treat this as a priority patch regardless of the EPSS number — the low score reflects market inefficiency, not your actual exposure. Verify your installed version, check for contributor-level accounts you didn't provision, and monitor your site for unusual shortcode configurations in post content.
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-16775 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
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