CVE-2026-62035: Upcasted S3 Offload missing authorization check vulnerability
medium 6.3 affects latest 3.1.0 published 2026-10-10 · updated 2026-10-13
- Affected versions
- 3.1.0 and older
- Fixed in
- no fix yet
- Latest version
- 3.1.0
- Severity
- Medium · CVSS 6.3
- Active installs
- 200+
- Type
- Missing authorization check
What an attacker needs
- Access: A low-level account on the site, such as a subscriber or customer (per the CVSS score).
CVSS vector (score by Patchstack): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
What to do now
- There is no fixed version yet. If you can manage without Upcasted S3 Offload for now, deactivate and delete it until the developer ships a fix.
- If you must keep it, cut down who can log in (remove unused accounts, especially low-level ones, and turn off open registration) and put a web application firewall in front of the site.
- Check the Upcasted S3 Offload page for a fix; it updates when the CVE feeds do.
- Not sure which version you run? Check your version against every known Upcasted S3 Offload issue.
With WP-CLI:
wp plugin get upcasted-s3-offload --field=version. - If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.
The advisory
Subscriber Broken Access Control in AWS S3 for WordPress Plugin – Upcasted <= 3.1.0 versions.
References
- NVD CVE-2026-62035 nvd.nist.gov
- Patchstack advisory patchstack.com
Related
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Where this data comes from
- CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
- Versions and install counts: wordpress.org/plugins/upcasted-s3-offload (Plugins API), fetched 2026-11-04.
- The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.