How severe is CVE-2026-42538?

CVE-2026-42538 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2026-42538 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-42538?

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

Does CVE-2026-42538 have an EU (EUVD) identifier?

Yes. CVE-2026-42538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34326.

When was CVE-2026-42538 published?

CVE-2026-42538 was published on 2026-06-04 and last updated on 2026-06-17.

CVE-2026-42538

CVE-2026-42538 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. 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-434.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34326
Weakness: CWE-434
Published: 2026-06-04
Last modified: 2026-06-17

Description

IRIS is a web collaborative platform that helps incident responders share technical details during investigations. Versions prior to 2.4.28 do not properly validate uploaded files. The application can therefore be misused to host phishing pages, amongst other things. This also creates another instance of a Cross-Site Scripting (XSS) vulnerability. Version 2.4.28 contains a patch.

Frequently asked questions

What is CVE-2026-42538?: IRIS is a web collaborative platform that helps incident responders share technical details during investigations. Versions prior to 2.4.28 do not properly validate uploaded files. The application can therefore be misused to host phishing pages, amongst other things. This also creates another instance of a Cross-Site Scripting (XSS) vulnerability. Version 2.4.28 contains a patch.
How severe is CVE-2026-42538?: CVE-2026-42538 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2026-42538 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-42538?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-42538 have an EU (EUVD) identifier?: Yes. CVE-2026-42538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34326.
When was CVE-2026-42538 published?: CVE-2026-42538 was published on 2026-06-04 and last updated on 2026-06-17.

References

Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

CVE-2026-48283 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-48276 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-57700 — Critical (CVSS 10.0): Unrestricted Upload of File with Dangerous Type vulnerability in Daan.Dev OMGF Pro allows Using Malicious Files. This…
CVE-2025-69129 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in WordPress & WooCommerce Scraper Plugin, Import Data from Any Site <= 1.0.7…
CVE-2026-40772 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions.
CVE-2026-40412 — Critical (CVSS 10.0): Unrestricted upload of file with dangerous type in Azure Orbital Spatio allows an unauthorized attacker to execute code…

Browse all CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities →