How severe is CVE-2026-23891?

CVE-2026-23891 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-23891 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23891?

CVE-2026-23891 affects Decidim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23891?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-23891 have an EU (EUVD) identifier?

Yes. CVE-2026-23891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22024.

When was CVE-2026-23891 published?

CVE-2026-23891 was published on 2026-04-13 and last updated on 2026-06-17.

CVE-2026-23891

CVE-2026-23891 is a high-severity vulnerability in Decidim with a CVSS 3.x base score of 8.7. 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-79.

Key facts

Severity: High (CVSS 3.x base score 8.7)
CVSS v4: 9.3
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-22024
Weakness: CWE-79
Affected product: Decidim
Published: 2026-04-13
Last modified: 2026-06-17

Description

Decidim is a participatory democracy framework. In versions below 0.30.5 and 0.31.0.rc1 through 0.31.0, a stored code execution vulnerability in the user name field allows a low-privileged attacker to execute arbitrary code in the context of any user who passively visits a comment page, resulting in high confidentiality and integrity impact across security boundaries. This issue has been fixed in versions 0.30.5 and 0.31.1.

Frequently asked questions

What is CVE-2026-23891?: Decidim is a participatory democracy framework. In versions below 0.30.5 and 0.31.0.rc1 through 0.31.0, a stored code execution vulnerability in the user name field allows a low-privileged attacker to execute arbitrary code in the context of any user who passively visits a comment page, resulting in high confidentiality and integrity impact across security boundaries. This issue has been fixed in versions 0.30.5 and 0.31.1.
How severe is CVE-2026-23891?: CVE-2026-23891 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-23891 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23891?: CVE-2026-23891 affects Decidim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23891?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-23891 have an EU (EUVD) identifier?: Yes. CVE-2026-23891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22024.
When was CVE-2026-23891 published?: CVE-2026-23891 was published on 2026-04-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:decidim:decidim:*:*:*:*:*:ruby:*:*

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