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CVE-2026-76610MediumCVSS 6.9CVE published 20 August 2026Added to mySites.guru 20 August 2026

ZOO (com_zoo) 4.1.64 - Unauthenticated Tag Modification

ZOO 4.1.64 fixed the three critical unauthenticated flaws present in 4.1.63 and below (CVE-2026-74803 arbitrary file upload leading to remote code execution, CVE-2026-74804 SQL injection, CVE-2026-75114 open redirect), but its tag-management hardening was incomplete. That gap is now published as CVE-2026-76610 (CVSS 4.0 base 6.9 Medium, AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N), credited to Phil Taylor of mySites.guru, with an affected range of 1.0.0 to 4.1.64. The Joomla CNA records it as unauthenticated tag modification, stating that the comment controller endpoint lacked ACL checks and so allowed tags to be altered with no login at all. Reading the shipped 4.1.64 package shows the matching administrator-side gap as well: the admin tag controller gained CSRF tokens on its remove and update tasks and a canManageTags() helper was added to the framework, but nothing in the package ever calls that helper and the zoo.tags.manage permission is absent from access.xml, so tag rename and tag delete were gated only by the component-wide core.manage check. On either reading the impact is to content integrity. This is NOT the CVSS 10.0 remote code execution, which 4.1.64 genuinely does fix. YOOtheme shipped the tag fix in 4.1.65 on 19 August 2026, hours after 4.1.64. Do not stop there. ZOO 4.1.66, released on 21 August 2026, fixed three further published CVEs on the front-end submission path (CVE-2026-76611 unauthenticated arbitrary directory listing, CVE-2026-77028 reflected XSS and open redirect, CVE-2026-77029 missing CSRF protection) plus two unannounced hardening fixes on the upload path. Update to ZOO 4.1.66 or later. If you cannot update immediately, restrict backend access to com_zoo to trusted administrators and restrict guest access to any published front-end submission form.

Is my site affected?

Affected
ZOO from 4.1.64 up to but not including 4.1.65
Fixed in
4.1.65
What to do
Update ZOO to 4.1.65 for this flaw, or to 4.1.66 or later, which no rule we check matches.
Check whether your sites are affected

How CVE-2026-76610 is scored

The base metrics as Joomla CNA published them, and what each one means for a site running an affected version. Threat and environmental metrics are left out: they describe a moment or a particular install rather than the flaw.

6.9 Medium

CVSS 4.0, scored by Joomla CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

How it is reached

AV:N Attack vector
Network. Reachable across the internet
AC:L Attack complexity
Low. Nothing to work around, it just works
AT:N Attack requirements
None. Works against any affected install
PR:N Privileges required
None. No account needed
UI:N User interaction
None. Nobody has to be tricked into anything

What it does to the site

VC:N Confidentiality
None. Nothing can be read
VI:L Integrity
Low. Some data can be altered
VA:N Availability
None. The site stays up

What it does beyond the site

SC:N Confidentiality
None. Other systems keep their data
SI:N Integrity
None. Other systems keep their integrity
SA:N Availability
None. Other systems stay up

Timeline

  1. 20 August 2026CVE-2026-76610 record published by its CNA
  2. 20 August 2026mySites.guru check added for ZOO (from 4.1.64 up to but not including 4.1.65)

Rule details

Other vulnerabilities in ZOO

Updating for CVE-2026-76610 alone can leave a site on a release another rule still matches. These are the other flaws we check for in the same extension.

ZOO

Latest safe version: 4.1.66

References

CVE-2026-76610 questions

Which versions are affected by CVE-2026-76610?
CVE-2026-76610 affects ZOO from 4.1.64 up to but not including 4.1.65. The fix is in 4.1.65.
How do I fix CVE-2026-76610?
Update ZOO to 4.1.65 for this flaw, or to 4.1.66 or later, which no rule we check matches. Then confirm the installed version on the Joomla administrator's Extensions: Manage screen.
How severe is CVE-2026-76610?
Joomla CNA scores it 6.9 (Medium) under CVSS 4.0. In plain terms: reachable across the internet, no account needed and nobody has to be tricked into anything.

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This check is part of the mySites.guru Joomla vulnerability scanner, which reads every installed extension's version on each audit. Browse the rest of the Joomla vulnerability database.

Rules current as of 5 October 2026.