How severe is CVE-2026-7890?

CVE-2026-7890 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-7890 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-7890?

CVE-2026-7890 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-7890?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-7890 have an EU (EUVD) identifier?

Yes. CVE-2026-7890 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31379.

When was CVE-2026-7890 published?

CVE-2026-7890 was published on 2026-05-21 and last updated on 2026-06-17.

CVE-2026-7890

CVE-2026-7890 is a medium-severity vulnerability in Concretecms Concrete Cms with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
CVSS v4: 2.1
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31379
Weakness: CWE-918
Affected product: Concretecms Concrete Cms
Published: 2026-05-21
Last modified: 2026-06-17

Description

In Concrete CMS 9.5.0 and below, the RSS Displayer block accepts a feed URL from any page editor and fetches it server-side without validation enabling redirect-to-internal bypasses. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.1 with a vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N.

Frequently asked questions

What is CVE-2026-7890?: In Concrete CMS 9.5.0 and below, the RSS Displayer block accepts a feed URL from any page editor and fetches it server-side without validation enabling redirect-to-internal bypasses. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.1 with a vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N.
How severe is CVE-2026-7890?: CVE-2026-7890 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-7890 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-7890?: CVE-2026-7890 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-7890?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-7890 have an EU (EUVD) identifier?: Yes. CVE-2026-7890 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31379.
When was CVE-2026-7890 published?: CVE-2026-7890 was published on 2026-05-21 and last updated on 2026-06-17.

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes

Affected products (1)

cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*

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