CVE
jDownloads extension for Joomla remote code execution via frontend thumbnail upload
Affects the jDownloads extension for Joomla 5 and 6 before 4.1.8. Fixed in 4.1.8.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 4.1.8
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 4.1.8.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.44% · 38th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 30/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: total
Summary
The jDownloads extension for Joomla from jdownloads.com has insufficient validation of frontend thumbnail uploads, which lets an attacker remotely, without logging in, place executable files on the server. This results in PHP code execution on the server.
Read the original description
Joomla Extension - jdownloads.com - RCE through file upload in jDownloads < 4.1.8 - Insufficient validation of frontend thumbnail uploads allowed users with upload permission to place executable files on the server. This results in PHP code execution.
Who should check
Sites running the jDownloads Joomla extension before 4.1.8 on Joomla 5 or Joomla 6
Read the source excerpt
“jDownloads 4.1.8 Stable security update for Joomla 5 and 6 is available.”
cve.now Index
- Exploitation0/40No signal
- Exposure20/25No login or user action needed, CISA rates it automatable · Unknown: Advisories don't say whether default setups are affected
- Reach?/20Unknown. No tracked technology or package matched
- Severity10/10CVSS 10.0, total technical impact per CISA
- No patch0/5No signal
What would change the score
- Would score about 75 if added to CISA KEV
- Would score about 70 if CISA's SSVC rates exploitation active
- Would score about 35 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 4.1.8.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-117551 (Joomla Extension - jdownloads.com - RCE through file upload in jDownloads < 4.1.8), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-117551 (entry last updated 2026-11-13):
Affected:
- jdownloads.com jDownloads extension for Joomla: versions 1.0.0-4.1.7
Fixed versions: 4.1.8.
Conditions (all must be true for the bug to be hit):
- Joomla 5 or Joomla 6 site running jDownloads (source: https://www.jdownloads.com/)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-117551 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-117551 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://www.jdownloads.com/
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-117551
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-117551"}.Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: total
1 day - Record last updated
Affected versions
- jdownloads.com jDownloads extension for Joomla
1.0.0-4.1.7
Evidence 3
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-117551
Is CVE-2026-117551 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The flaw is a file upload weakness in jDownloads that can lead to remote code execution on the affected Joomla site.Source: jdownloads.com
Which versions are affected by CVE-2026-117551?
jDownloads extension for Joomla: version 1.0.0-4.1.7.Source: cve.now feed data
Am I affected, and how do I check?
Versions of the jDownloads extension before 4.1.8 running on Joomla 5 or Joomla 6 are affected. To check, look at the installed jDownloads version in the Joomla extensions manager.Source: jdownloads.com
How do I fix CVE-2026-117551?
Update the jDownloads extension to version 4.1.8, the fixed release named in the vendor's security update for Joomla 5 and 6.Source: jdownloads.com