CVE-2026-126084

Source
https://cve.org/CVERecord?id=CVE-2026-126084
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-126084.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-126084
Aliases
  • GHSA-3w93-6hmw-whh4
Downstream
Published
2026-11-10T21:11:00Z
Modified
2026-11-11T10:47:26Z
Severity
  • 4.7 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
Summary
Active Storage: Unsigned Content-Type in Active Storage GCS direct uploads with cache_control
Details

Active Storage makes it simple to upload and reference files in cloud services and attach those files to Active Record objects. Prior to 8.1.4.1 and 8.0.5.2, when a GCS service is configured with the cache_control option, ActiveStorage::Service::GCSService#url_for_direct_upload signs direct-upload URLs with V4, and the V4 signature covers only the Cache-Control and Host headers. A direct-upload client can therefore send a Content-Type of its choosing, and can omit the declared Content-MD5, without invalidating the URL. GCS stores the supplied content type as object metadata, which takes precedence over the response-content-type that Active Storage sets on download URLs, so an uploaded object could be served as inline HTML under the application's bucket path on storage.googleapis.com. Script in such an object runs on the storage origin rather than the application's, but could register a Service Worker scoped to the bucket path and read or replace a victim's later responses for signed URLs in that bucket. Applications that use the GCS service with cache_control configured and accept direct uploads are affected. GCS services without cache_control sign with V2 and are not affected. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.

Database specific
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-345"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126084.json"
}
References

Affected packages

Git / github.com/rails/rails

Affected ranges

Type
GIT
Repo
https://github.com/rails/rails
Events
Database specific
Show details
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "8.1"
                },
                {
                    "fixed": "8.1.4.1"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "fixed": "8.0.5.2"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "fixed": "8d93f6a872e9550a91bf0e4fce50083a235ef3b1"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "range": [
                {
                    "fixed": "ddc08ba61a8001e7402864c62e466cf732fc7614"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "original_tag": "v8.0.5.2",
            "range": [
                {
                    "fixed": "235c597b100321b6bd2d62f8df63707f42b25b2d"
                }
            ],
            "source": "REFERENCES_TAG"
        },
        {
            "original_tag": "v8.1.4.1",
            "range": [
                {
                    "fixed": "3f290b759c8e2ffe7c257951b1255740751355e4"
                }
            ],
            "source": "REFERENCES_TAG"
        }
    ]
}

Affected versions

v0.*
v0.10.0
v0.10.1
v0.11.0
v0.11.1
v0.12.0
v0.13.0
v0.13.1
v0.14.1
v0.14.3
v0.9.1
v0.9.2
v0.9.3
v0.9.4
v0.9.4.1
v0.9.5
v1.*
v1.1.0
v1.1.0_RC1
v1.1.1
v2.*
v2.0.0
v2.0.0_PR
v2.0.0_RC1
v2.0.0_RC2
v2.0.1
v3.*
v3.0.0.beta.3
v3.0.0.beta3
v3.1.0.beta1
v3.1.0.rc1
v3.2.0.rc1
v4.*
v4.0.0.beta1
v4.0.0.rc1
v4.2.0.beta1
v5.*
v5.0.0.beta1
v5.0.0.beta2
v5.0.0.beta4
v5.1.0.beta1
v6.*
v6.0.0.beta1
v6.0.0.beta2
v6.1.0.rc1
v7.*
v7.0.0.alpha1
v7.0.0.alpha2
v7.1.0.beta1
v8.*
v8.0.0
v8.0.0.beta1
v8.0.0.rc1
v8.0.0.rc2
v8.0.1
v8.0.2
v8.0.3
v8.0.4
v8.0.5
v8.0.5.1
v8.1.0
v8.1.1
v8.1.2
v8.1.3
v8.1.4

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-126084.json"