CVE-2026-48943: K2 ≤ 2.24 contains a mass-assignment defect in the K2 system user plugin `plg_user_k2`

Q: How do I fix CVE-2026-48943?

k2: upgrade to newer than 2.26. Exact commands for each OS are on this page.

Q: Is CVE-2026-48943 being exploited?

CVE-2026-48943 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-48943 affect?

CVE-2026-48943 affects k2. Severity is medium (CVSS 6.5). K2 ≤ 2.24 contains a mass-assignment defect in the K2 system user plugin `plg_user_k2`. A Registered Joomla user, by including the field `K2UserForm=1` in a standard `com_users` `profile.save` POST, can write arbitrary values into the `note

Q: How urgent is CVE-2026-48943?

Priority 33/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 6.5REMOTEUPGRADE

CVE-2026-48943 is a medium-severity flaw (CVSS 6.5) affecting k2. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

K2 ≤ 2.24 contains a mass-assignment defect in the K2 system user plugin `plg_user_k2`. A Registered Joomla user, by including the field `K2UserForm=1` in a standard `com_users` `profile.save` POST, can write arbitrary values into the `notes`, `image`, and `plugins` columns of their own row in the `#__k2_users` table — none of which are exposed by the K2 frontend profile-edit form.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-915
Published	2026-06-25
Last modified	2026-10-25

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

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

Am I affected?

Timeline

2026-06-25 16:16 UTCPublished CVE record published
2026-10-25 22:10 UTCUpdated Record last modified

joomlaworks k2 UPGRADE

Affected: <= 2.26

Fixed in: newer than 2.26

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy k2 || rpm -q k2 || k2 --version

2. UPGRADE to newer than 2.26 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade k2

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade k2

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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.

Quick answers

How do I fix CVE-2026-48943?

k2: upgrade to newer than 2.26. Exact commands for each OS are on this page.

Is CVE-2026-48943 being exploited?

CVE-2026-48943 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48943 affect?

CVE-2026-48943 affects k2. Severity is medium (CVSS 6.5). K2 ≤ 2.24 contains a mass-assignment defect in the K2 system user plugin `plg_user_k2`. A Registered Joomla user, by including the field `K2UserForm=1` in a standard `com_users` `profile.save` POST, can write arbitrary values into the `note

How urgent is CVE-2026-48943?

Priority 33/100. Remotely exploitable, no login, no user action

Software pages

Joomla vulnerabilities

Related CVEs

CVE-2026-48941 MEDIUM 6.5 UPGRADE The K2 frontend `item.checkin` task accepts an unauthenticated `sigProFolder` query parameter and uses it dire
CVE-2026-48944 MEDIUM 6.5 UPGRADE The K2 frontend article-save handler accepts an `attachment[N][existing]` POST field that is concatenated with
CVE-2026-48946 MEDIUM 6.3 UPGRADE The K2 frontend article-attachment upload path accepts files whose extension is `.php`, and Apache's standard
CVE-2026-48945 MEDIUM 5.3 UPGRADE The K2 article gallery upload path accepts a zip/tar archive, extracts it under `/media/k2/galleries/<id>/`, a
CVE-2026-48942 MEDIUM 6.1 UPGRADE K2 ≤ 2.26 renders the `#__k2_users.image` column directly into HTML `src` attributes via two distinct template

References

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