Security readout for executives and security teams
Plain-English summary
CVE-2026-4335 affects the ShortPixel Image Optimizer WordPress plugin through version 6.4.3. A logged-in Author or higher can save a malicious attachment title that may run script when an administrator opens ShortPixel’s AI editor popup for that attachment. This is not listed in KEV, and the sources do not report active exploitation.
Executive priority
Treat as a moderate-priority WordPress plugin issue. It is not known to be actively exploited, but it can turn a lower-privileged content account into a browser-based attack against administrators. Prioritize sites with many contributors, external authors, or high-value WordPress admin access.
Technical view
The issue is stored XSS in getEditorPopup() and media-popup.php. An attachment post_title from get_post() is rendered into an HTML input value without proper attribute escaping. WordPress Authors can control attachment titles, enabling script injection that executes with user interaction when a privileged user opens the affected ShortPixel popup.
Likely exposure
WordPress sites using ShortPixel Image Optimizer versions up to and including 6.4.3 are potentially exposed, especially sites allowing untrusted Author-level users or content contributors. Sites without the plugin, without Author-level untrusted users, or not using affected ShortPixel AI popup workflows have lower practical exposure.
Exploitation context
Exploitation requires authenticated Author-level access or higher and a higher-privileged user to open the affected ShortPixel editor popup for the poisoned attachment. The CVSS score is 5.4. The source bundle indicates no KEV listing and provides no evidence of active exploitation in the wild.
Researcher notes
The described flaw is an escaping failure in an attribute context, mapped to CWE-79. The provided references identify the vulnerable data flow from AjaxController.php to media-popup.php and a WordPress.org changeset. The sources do not clearly name a fixed release, so remediation should be verified against vendor guidance.
Mitigation direction
- Update ShortPixel Image Optimizer if the vendor provides a fixed release.
- Check ShortPixel and WordPress plugin guidance for the confirmed fixed version.
- Restrict Author-level accounts to trusted users until remediated.
- Review contributor and author account activity for unusual media changes.
- Limit administrator interaction with suspicious media attachments until assessed.
Validation and detection
- Inventory WordPress sites using ShortPixel Image Optimizer.
- Identify installations running version 6.4.3 or earlier.
- Confirm whether a vendor-fixed version is installed when available.
- Review media attachment titles changed by Author-level users.
- Check logs for privileged users opening ShortPixel AI editor popups on suspicious attachments.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-4335 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/a156234f-2644-4d17-aaa5-4f088cf48f73?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/trunk/class/view/snippets/media-popup.php#L139CVE reference
- https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.4.3/class/view/snippets/media-popup.php#L139CVE reference
- https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/trunk/class/Controller/AjaxController.php#L449CVE reference
- https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.4.3/class/Controller/AjaxController.php#L449CVE reference
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3490270%40shortpixel-image-optimiser&new=3490270%40shortpixel-image-optimiser&sfp_email=&sfph_mail=CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.