PatchTheCVECVE-2026-73373: Joomla! Core - [20260810] - Unrestricted uploads of SHTML files in Joomla 1.0.0-5.4.7, 6.0.0-6.1.2 - The defau
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This month
CRITICAL 9.8REMOTEUPGRADE
CVE-2026-73373 is a critical-severity flaw (CVSS 9.8) affecting joomla\!. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Joomla! Core - [20260810] - Unrestricted uploads of SHTML files in Joomla 1.0.0-5.4.7, 6.0.0-6.1.2 - The default list of dangerous files did not include SHTML files. On servers that executed these files, that could lead to code execution.
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.6% (top 50%) |
| CISA exploited list | No |
| Weakness | CWE-434 |
| Published | 2026-08-18 |
| Last modified | 2026-10-22 |
Publisher (CNA): Joomla! Project · Vendor: joomla
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
joomla joomla\! UPGRADE
Affected: >= 1.0.0 and < 5.4.8 · >= 6.0.0 and < 6.1.3
Fixed in: 5.4.8, 6.1.3
Safe to downgrade to: a release before 1.0.0
1. Check installed version
apt-cache policy joomla || rpm -q joomla || joomla --version
2. UPGRADE to 5.4.8 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade joomla
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade joomla
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)
apt-cache madison joomla
sudo apt install joomla=<VERSION_BEFORE_1.0.0>
sudo apt-mark hold joomla
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list joomla
sudo dnf downgrade joomla-<VERSION_BEFORE_1.0.0>
sudo dnf versionlock add joomla
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Exact fixes by distribution
Fedora 46 · python-streamlink · FIXED · 8.6.2-1.fc46 · FEDORA-2026-a56fcfdc08 · source
sudo dnf upgrade --advisory=FEDORA-2026-a56fcfdc08
Fedora ELN · valgrind · FIXED · 3.28.0-1.eln159 · FEDORA-2026-c593ef1d15 · source
sudo dnf upgrade --advisory=FEDORA-2026-c593ef1d15
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
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