How severe is CVE-2026-25500?

CVE-2026-25500 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-25500 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-25500?

CVE-2026-25500 affects Rack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-25500?

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

Does CVE-2026-25500 have an EU (EUVD) identifier?

Yes. CVE-2026-25500 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7916.

When was CVE-2026-25500 published?

CVE-2026-25500 was published on 2026-02-18 and last updated on 2026-06-17.

CVE-2026-25500

CVE-2026-25500 is a medium-severity vulnerability in Rack with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-7916
Weakness: CWE-79
Affected product: Rack
Published: 2026-02-18
Last modified: 2026-06-17

Description

Rack is a modular Ruby web server interface. Prior to versions 2.2.22, 3.1.20, and 3.2.5, `Rack::Directory` generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename starts with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index contains an anchor whose `href` is exactly `javascript:alert(1)`. Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`). Versions 2.2.22, 3.1.20, and 3.2.5 fix the issue.

Frequently asked questions

What is CVE-2026-25500?: Rack is a modular Ruby web server interface. Prior to versions 2.2.22, 3.1.20, and 3.2.5, `Rack::Directory` generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename starts with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index contains an anchor whose `href` is exactly `javascript:alert(1)`. Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`). Versions 2.2.22, 3.1.20, and 3.2.5 fix the issue.
How severe is CVE-2026-25500?: CVE-2026-25500 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-25500 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-25500?: CVE-2026-25500 affects Rack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-25500?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-25500 have an EU (EUVD) identifier?: Yes. CVE-2026-25500 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7916.
When was CVE-2026-25500 published?: CVE-2026-25500 was published on 2026-02-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*

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