CVE-2026-33195: Activestorage Path Traversal Vulnerability
HIGHCVE-2026-33195 is a HIGH path traversal vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Activestorage libraries in the RubyGems ecosystem. The issue involves rails active storage has possible path traversal in diskservice. Remediation is available by upgrading affected packages to version 8.1.2.1, 8.0.4.1, 7.2.3.1.
CVE-2026-33195 at a Glance
How to Fix CVE-2026-33195
To remediate this vulnerability, upgrade all affected Activestorage dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade activestorage to 8.1.2.1Upgrade activestorage to 8.0.4.1Upgrade activestorage to 7.2.3.1Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for activestorageHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-33195, inspect your project dependencies for Activestorage:
inspect dependencies for activestorageAnalyze the terminal output to locate any version of Activestorage in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.1.2.1), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Activestorage, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-33195 Affected Activestorage Versions
3 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
activestorage
|
RubyGems |
≥ 8.1.0.beta1
< 8.1.2.1
|
8.1.2.1
|
|
activestorage
|
RubyGems |
≥ 8.0.0.beta1
< 8.0.4.1
|
8.0.4.1
|
|
activestorage
|
RubyGems |
< 7.2.3.1
|
7.2.3.1
|
References
Frequently Asked Questions
What is CVE-2026-33195?
Which Activestorage versions are affected?
What version fixes CVE-2026-33195?
Is activestorage affected?
What CWE is associated with CVE-2026-33195?
How can I check RubyGems dependencies for CVE-2026-33195?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-9xrj-h377-fr87",
"modified" : "2026-05-13T16:16:55Z",
"published" : "2026-03-23T21:17:19Z",
"aliases" : [ "CVE-2026-33195" ],
"summary" : "Rails Active Storage has possible Path Traversal in DiskService",
"details" : "### Impact\nActive Storage's `DiskService#path_for` does not validate that the resolved filesystem path remains within the storage root directory. If a blob key containing path traversal sequences (e.g. `../`) is used, it could allow reading, writing, or deleting arbitrary files on the server. Blob keys are expected to be trusted strings, but some applications could be passing user input as keys and would be affected.\n\n### Releases\nThe fixed releases are available at the normal locations.\n\n### Credit\nThis issue was responsibly reported by Hackerone researcher [ksw9722](https://hackerone.com/ksw9722).",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "RubyGems",
"name" : "activestorage"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "8.1.0.beta1"
}, {
"fixed" : "8.1.2.1"
} ]
} ]
}, {
"package" : {
"ecosystem" : "RubyGems",
"name" : "activestorage"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "8.0.0.beta1"
}, {
"fixed" : "8.0.4.1"
} ]
} ]
}, {
"package" : {
"ecosystem" : "RubyGems",
"name" : "activestorage"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "7.2.3.1"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/rails/rails/security/advisories/GHSA-9xrj-h377-fr87"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33195"
}, {
"type" : "WEB",
"url" : "https://github.com/rails/rails/commit/4933c1e3b8c1bb04925d60347be9f69270392f2c"
}, {
"type" : "WEB",
"url" : "https://github.com/rails/rails/commit/9b06fbc0f504b8afe333f33d19548f3b85fbe655"
}, {
"type" : "WEB",
"url" : "https://github.com/rails/rails/commit/a290c8a1ec189d793aa6d7f2570b6a763f675348"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/rails/rails"
}, {
"type" : "WEB",
"url" : "https://github.com/rails/rails/releases/tag/v7.2.3.1"
}, {
"type" : "WEB",
"url" : "https://github.com/rails/rails/releases/tag/v8.0.4.1"
}, {
"type" : "WEB",
"url" : "https://github.com/rails/rails/releases/tag/v8.1.2.1"
}, {
"type" : "WEB",
"url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33195.yml"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-22" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-23T21:17:19Z",
"nvd_published_at" : "2026-03-24T00:16:28Z"
}
}