How severe is CVE-2026-33174?

CVE-2026-33174 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-33174 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33174?

CVE-2026-33174 affects Rubyonrails Rails. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33174?

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-2026-33174 have an EU (EUVD) identifier?

Yes. CVE-2026-33174 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14628.

When was CVE-2026-33174 published?

CVE-2026-33174 was published on 2026-03-24 and last updated on 2026-06-17.

CVE-2026-33174

CVE-2026-33174 is a high-severity vulnerability in Rubyonrails Rails with a CVSS 3.x base score of 7.5. 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-789.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.6
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14628
Weakness: CWE-789
Affected product: Rubyonrails Rails
Published: 2026-03-24
Last modified: 2026-06-17

Description

Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, when serving files through Active Storage's proxy delivery mode, the proxy controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. `bytes=0-`) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

Frequently asked questions

What is CVE-2026-33174?: Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, when serving files through Active Storage's proxy delivery mode, the proxy controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. `bytes=0-`) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
How severe is CVE-2026-33174?: CVE-2026-33174 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33174 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33174?: CVE-2026-33174 affects Rubyonrails Rails. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33174?: 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-2026-33174 have an EU (EUVD) identifier?: Yes. CVE-2026-33174 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14628.
When was CVE-2026-33174 published?: CVE-2026-33174 was published on 2026-03-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*

More vulnerabilities in Rubyonrails Rails

CVE-2013-0277 — Critical (CVSS 10.0): ActiveRecord in Ruby on Rails before 2.3.17 and 3.x before 3.1.0 allows remote attackers to cause a denial of service…
CVE-2026-33195 — Critical (CVSS 9.8): Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1,…
CVE-2020-8165 — Critical (CVSS 9.8): A deserialization of untrusted data vulnernerability exists in rails < 5.2.4.3, rails < 6.0.3.1 that can allow an…
CVE-2019-5420 — Critical (CVSS 9.8): A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess…
CVE-2026-33202 — Critical (CVSS 9.1): Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1,…
CVE-2020-8163 — High (CVSS 8.8): The is a code injection vulnerability in versions of Rails prior to 5.0.1 that wouldallow an attacker who controlled…

All CVEs affecting Rubyonrails Rails →

Other CWE-789 vulnerabilities

CVE-2021-34869 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop…
CVE-2021-34868 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop…
CVE-2024-20260 — High (CVSS 8.6): A vulnerability in the VPN and management web servers of the Cisco Adaptive Security Virtual Appliance (ASAv) and Cisco…
CVE-2021-34867 — High (CVSS 8.2): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop…
CVE-2026-20048 — High (CVSS 7.7): A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco Nexus 9000 Series Fabric Switches…
CVE-2026-55380 — High (CVSS 7.5): Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from…

Browse all CWE-789 vulnerabilities →