CVE-2026-48939: iCagenda Unrestricted Upload of File with Dangerous Type Vulnerability

Q: How do I fix CVE-2026-48939?

icagenda: upgrade to 3.9.15, 4.0.8. Exact commands for each OS are on this page.

Q: Is CVE-2026-48939 being exploited?

Yes. CVE-2026-48939 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2026-48939 affect?

CVE-2026-48939 affects icagenda. Severity is critical (CVSS 9.8). A vulnerability in the iCagenda extension for Joomla allows the upload of arbitrary files in the file attachment feature, ultimately resulting in PHP code upload and execution.

Q: How urgent is CVE-2026-48939?

Priority 97/100. Critical severity; EPSS top 3%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Patch now

CRITICAL 9.8EXPLOITEDREMOTEUPGRADE

CVE-2026-48939 is a critical-severity flaw (CVSS 9.8) affecting icagenda, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in the iCagenda extension for Joomla allows the upload of arbitrary files in the file attachment feature, ultimately resulting in PHP code upload and execution.

Why this priority

Critical severity
EPSS top 3%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
CISA SSVC: automatable with total technical impact
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	20.1% (top 3%)
CISA exploited list	Yes, fix due 2026-07-13
Weakness	CWE-434
Published	2026-06-20
Last modified	2026-10-25

Publisher (CNA): Joomla! Project · Vendor: joomlic

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-20 13:16 UTCPublished CVE record published
2026-07-10Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-07-13Deadline CISA due date for US federal agencies to patch
2026-10-25 23:10 UTCUpdated Record last modified

joomlic icagenda UPGRADE

Affected: >= 3.2.1 and < 3.9.15 · >= 4.0.0 and < 4.0.8

Fixed in: 3.9.15, 4.0.8

Safe to downgrade to: a release before 3.2.1

1. Check installed version

apt-cache policy icagenda || rpm -q icagenda || icagenda --version

2. UPGRADE to 3.9.15 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade icagenda

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade icagenda

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 3.2.1 (Debian / Ubuntu)

apt-cache madison icagenda sudo apt install icagenda=<VERSION_BEFORE_3.2.1> sudo apt-mark hold icagenda

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list icagenda sudo dnf downgrade icagenda-<VERSION_BEFORE_3.2.1> sudo dnf versionlock add icagenda

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 · mingw-qt5-qtwebkit · FIXED · 5.212.0-0.46.alpha4.fc46 · FEDORA-2026-46ae541c22 · source

sudo dnf upgrade --advisory=FEDORA-2026-46ae541c22

Fedora ELN · kdominate · FIXED · 26.08.2-2.eln159 · FEDORA-2026-b1d98239fd · source

sudo dnf upgrade --advisory=FEDORA-2026-b1d98239fd

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: shinthink/CVE-2026-48939 (2 stars)
GitHub PoC: Polosss/By-Poloss..-..CVE-2026-48939 (1 stars)
GitHub PoC: ChiefYoru/CVE-2026-48939_PoC (0 stars)
Write-up: mysites.guru/blog/icagenda-zero-day-file-upload-rce/
Nuclei scan template: Joomla iCagenda < 3.9.10 - Unauthenticated Arbitrary File Upload RCE

Verify at the official source NVD · CVE Program · CISA KEV catalog · 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.

Quick answers

How do I fix CVE-2026-48939?

icagenda: upgrade to 3.9.15, 4.0.8. Exact commands for each OS are on this page.

Is CVE-2026-48939 being exploited?

Yes. CVE-2026-48939 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-48939 affect?

CVE-2026-48939 affects icagenda. Severity is critical (CVSS 9.8). A vulnerability in the iCagenda extension for Joomla allows the upload of arbitrary files in the file attachment feature, ultimately resulting in PHP code upload and execution.

How urgent is CVE-2026-48939?

Priority 97/100. Critical severity; EPSS top 3%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Joomla vulnerabilities · PHP vulnerabilities

References

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