CVE-2026-33174: medium-severity vulnerability in rails activestorage
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
Published · Updated
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.6epss 0.7%
exploitation probability
0.7%top 48% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
Affected products
rails · activestorageRelated CVEs — rails activestorage
In the same product, most dangerous first.
CVE-2026-33202MEDIUMRails Active Storage has possible glob injection in its DiskServiceEPSS 0.8%CVE-2026-33195HIGHRails Active Storage has possible Path Traversal in DiskServiceEPSS 0.7%CVE-2026-33658LOWRails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requestsEPSS 0.6%CVE-2026-33173MEDIUMRails Active Storage has possible content type bypass via metadata in direct uploadsEPSS 0.4%
References
https://github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5https://github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92ahttps://github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229bhttps://github.com/rails/rails/releases/tag/v7.2.3.1https://github.com/rails/rails/releases/tag/v8.0.4.1https://github.com/rails/rails/releases/tag/v8.1.2.1https://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg