# CVE-2026-126085: Active Storage: Possible circumvention of file size limits in Active Storage direct uploads to Google Cloud Storage

Status: published. Published: 2026-11-10. Updated: 2026-11-14.

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, ActiveStorage::Service::GCSService#url_for_direct_upload does not bind the declared content length into the signed direct-upload URL, and #headers_for_direct_upload returns no length constraint, so the URL authorizes an upload body of any size. A direct-upload client could store a file larger than the byte_size it declared, and the resulting blob keeps the declared size, possibly bypassing application file size validations and quotas. This is the weakness that CVE-2020-8162 fixed in the S3 service. Applications that store files in Google Cloud Storage and accept direct uploads are affected. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.

## Remediation

- fix: activestorage (RubyGems): OSV reports a fixed version 8.1.4.1. Check the advisory for supported release branches. (source: OSV GHSA-hfr4-8rjc-97m2) — https://github.com/advisories/GHSA-hfr4-8rjc-97m2
- fix: activestorage (RubyGems): OSV reports a fixed version 8.0.5.2. Check the advisory for supported release branches. (source: OSV GHSA-hfr4-8rjc-97m2) — https://github.com/advisories/GHSA-hfr4-8rjc-97m2

## Affected products and versions

- rails / rails: >= 8.1, < 8.1.4.1 (affected); < 8.0.5.2 (affected). Source: CNA: GitHub_M
-  / activestorage (activestorage): 8.1.0 (affected, RubyGems); 8.1.0.beta1 (affected, RubyGems); 8.1.0.rc1 (affected, RubyGems); 8.1.1 (affected, RubyGems); 8.1.2 (affected, RubyGems); 8.1.2.1 (affected, RubyGems); 8.1.3 (affected, RubyGems); 8.1.3.1 (affected, RubyGems); 8.1.4 (affected, RubyGems); Ecosystem version events: introduced 8.1.0.beta1; fixed 8.1.4.1. Source: OSV GHSA-hfr4-8rjc-97m2
-  / activestorage (activestorage): 0.1 (affected, RubyGems); 5.2.0 (affected, RubyGems); 5.2.0.beta1 (affected, RubyGems); 5.2.0.beta2 (affected, RubyGems); 5.2.0.rc1 (affected, RubyGems); 5.2.0.rc2 (affected, RubyGems); 5.2.1 (affected, RubyGems); 5.2.1.1 (affected, RubyGems); 5.2.1.rc1 (affected, RubyGems); 5.2.2 (affected, RubyGems); 5.2.2.1 (affected, RubyGems); 5.2.2.rc1 (affected, RubyGems); 5.2.3 (affected, RubyGems); 5.2.3.rc1 (affected, RubyGems); 5.2.4 (affected, RubyGems); 5.2.4.1 (affected, RubyGems); 5.2.4.2 (affected, RubyGems); 5.2.4.3 (affected, RubyGems); 5.2.4.4 (affected, RubyGems); 5.2.4.5 (affected, RubyGems); 5.2.4.6 (affected, RubyGems); 5.2.4.rc1 (affected, RubyGems); 5.2.5 (affected, RubyGems); 5.2.6 (affected, RubyGems); 5.2.6.1 (affected, RubyGems); 5.2.6.2 (affected, RubyGems); 5.2.6.3 (affected, RubyGems); 5.2.7 (affected, RubyGems); 5.2.7.1 (affected, RubyGems); 5.2.8 (affected, RubyGems); 5.2.8.1 (affected, RubyGems); 6.0.0 (affected, RubyGems); 6.0.0.beta1 (affected, RubyGems); 6.0.0.beta2 (affected, RubyGems); 6.0.0.beta3 (affected, RubyGems); 6.0.0.rc1 (affected, RubyGems); 6.0.0.rc2 (affected, RubyGems); 6.0.1 (affected, RubyGems); 6.0.1.rc1 (affected, RubyGems); 6.0.2 (affected, RubyGems); 6.0.2.1 (affected, RubyGems); 6.0.2.2 (affected, RubyGems); 6.0.2.rc1 (affected, RubyGems); 6.0.2.rc2 (affected, RubyGems); 6.0.3 (affected, RubyGems); 6.0.3.1 (affected, RubyGems); 6.0.3.2 (affected, RubyGems); 6.0.3.3 (affected, RubyGems); 6.0.3.4 (affected, RubyGems); 6.0.3.5 (affected, RubyGems); 6.0.3.6 (affected, RubyGems); 6.0.3.7 (affected, RubyGems); 6.0.3.rc1 (affected, RubyGems); 6.0.4 (affected, RubyGems); 6.0.4.1 (affected, RubyGems); 6.0.4.2 (affected, RubyGems); 6.0.4.3 (affected, RubyGems); 6.0.4.4 (affected, RubyGems); 6.0.4.5 (affected, RubyGems); 6.0.4.6 (affected, RubyGems); 6.0.4.7 (affected, RubyGems); 6.0.4.8 (affected, RubyGems); 6.0.5 (affected, RubyGems); 6.0.5.1 (affected, RubyGems); 6.0.6 (affected, RubyGems); 6.0.6.1 (affected, RubyGems); 6.1.0 (affected, RubyGems); 6.1.0.rc1 (affected, RubyGems); 6.1.0.rc2 (affected, RubyGems); 6.1.1 (affected, RubyGems); 6.1.2 (affected, RubyGems); 6.1.2.1 (affected, RubyGems); 6.1.3 (affected, RubyGems); 6.1.3.1 (affected, RubyGems); 6.1.3.2 (affected, RubyGems); 6.1.4 (affected, RubyGems); 6.1.4.1 (affected, RubyGems); 6.1.4.2 (affected, RubyGems); 6.1.4.3 (affected, RubyGems); 6.1.4.4 (affected, RubyGems); 6.1.4.5 (affected, RubyGems); 6.1.4.6 (affected, RubyGems); 6.1.4.7 (affected, RubyGems); 6.1.5 (affected, RubyGems); 6.1.5.1 (affected, RubyGems); 6.1.6 (affected, RubyGems); 6.1.6.1 (affected, RubyGems); 6.1.7 (affected, RubyGems); 6.1.7.1 (affected, RubyGems); 6.1.7.10 (affected, RubyGems); 6.1.7.2 (affected, RubyGems); 6.1.7.3 (affected, RubyGems); 6.1.7.4 (affected, RubyGems); 6.1.7.5 (affected, RubyGems); 6.1.7.6 (affected, RubyGems); 6.1.7.7 (affected, RubyGems); 6.1.7.8 (affected, RubyGems); 6.1.7.9 (affected, RubyGems); 7.0.0 (affected, RubyGems); 7.0.0.alpha1 (affected, RubyGems); 7.0.0.alpha2 (affected, RubyGems); 7.0.0.rc1 (affected, RubyGems); 7.0.0.rc2 (affected, RubyGems); 7.0.0.rc3 (affected, RubyGems); 7.0.1 (affected, RubyGems); 7.0.10 (affected, RubyGems); 7.0.2 (affected, RubyGems); 7.0.2.1 (affected, RubyGems); 7.0.2.2 (affected, RubyGems); 7.0.2.3 (affected, RubyGems); 7.0.2.4 (affected, RubyGems); 7.0.3 (affected, RubyGems); 7.0.3.1 (affected, RubyGems); 7.0.4 (affected, RubyGems); 7.0.4.1 (affected, RubyGems); 7.0.4.2 (affected, RubyGems); 7.0.4.3 (affected, RubyGems); 7.0.5 (affected, RubyGems); 7.0.5.1 (affected, RubyGems); 7.0.6 (affected, RubyGems); 7.0.7 (affected, RubyGems); 7.0.7.1 (affected, RubyGems); 7.0.7.2 (affected, RubyGems); 7.0.8 (affected, RubyGems); 7.0.8.1 (affected, RubyGems); 7.0.8.2 (affected, RubyGems); 7.0.8.3 (affected, RubyGems); 7.0.8.4 (affected, RubyGems); 7.0.8.5 (affected, RubyGems); 7.0.8.6 (affected, RubyGems); 7.0.8.7 (affected, RubyGems); 7.1.0 (affected, RubyGems); 7.1.0.beta1 (affected, RubyGems); 7.1.0.rc1 (affected, RubyGems); 7.1.0.rc2 (affected, RubyGems); 7.1.1 (affected, RubyGems); 7.1.2 (affected, RubyGems); 7.1.3 (affected, RubyGems); 7.1.3.1 (affected, RubyGems); 7.1.3.2 (affected, RubyGems); 7.1.3.3 (affected, RubyGems); 7.1.3.4 (affected, RubyGems); 7.1.4 (affected, RubyGems); 7.1.4.1 (affected, RubyGems); 7.1.4.2 (affected, RubyGems); 7.1.5 (affected, RubyGems); 7.1.5.1 (affected, RubyGems); 7.1.5.2 (affected, RubyGems); 7.1.6 (affected, RubyGems); 7.2.0 (affected, RubyGems); 7.2.0.beta1 (affected, RubyGems); 7.2.0.beta2 (affected, RubyGems); 7.2.0.beta3 (affected, RubyGems); 7.2.0.rc1 (affected, RubyGems); 7.2.1 (affected, RubyGems); 7.2.1.1 (affected, RubyGems); 7.2.1.2 (affected, RubyGems); 7.2.2 (affected, RubyGems); 7.2.2.1 (affected, RubyGems); 7.2.2.2 (affected, RubyGems); 7.2.3 (affected, RubyGems); 7.2.3.1 (affected, RubyGems); 7.2.3.2 (affected, RubyGems); 7.2.4 (affected, RubyGems); 8.0.0 (affected, RubyGems); 8.0.0.1 (affected, RubyGems); 8.0.0.beta1 (affected, RubyGems); 8.0.0.rc1 (affected, RubyGems); 8.0.0.rc2 (affected, RubyGems); 8.0.1 (affected, RubyGems); 8.0.2 (affected, RubyGems); 8.0.2.1 (affected, RubyGems); 8.0.3 (affected, RubyGems); 8.0.4 (affected, RubyGems); 8.0.4.1 (affected, RubyGems); 8.0.5 (affected, RubyGems); 8.0.5.1 (affected, RubyGems); Ecosystem version events: introduced 0; fixed 8.0.5.2. Source: OSV GHSA-hfr4-8rjc-97m2

## Severity and prioritization

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: GitHub_M

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.48% as of 2026-11-13; percentile 41.99%

- SSVC: exploitation none; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-602

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/rails/rails/security/advisories/GHSA-hfr4-8rjc-97m2 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/rails/rails/commit/7fe85a72a789eae5ee070ce3ee1dad10a8a5f70c (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/rails/rails/commit/e19916cea31cbfb0030b165ae853b741f8dd57a7 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/rails/rails/releases/tag/v8.0.5.2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/rails/rails/releases/tag/v8.1.4.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/rails/rails/commit/7fe85a72a789eae5ee070ce3ee1dad10a8a5f70c (security-advisories@github.com)

- https://github.com/rails/rails/commit/e19916cea31cbfb0030b165ae853b741f8dd57a7 (security-advisories@github.com)

- https://github.com/rails/rails/releases/tag/v8.0.5.2 (security-advisories@github.com)

- https://github.com/rails/rails/releases/tag/v8.1.4.1 (security-advisories@github.com)

- https://github.com/rails/rails/security/advisories/GHSA-hfr4-8rjc-97m2 (security-advisories@github.com)

- https://github.com/advisories/GHSA-hfr4-8rjc-97m2 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-hfr4-8rjc-97m2 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-126085; retrieved 2026-11-14; source updated 2026-11-14

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126085; retrieved 2026-11-13; source updated 2026-11-12

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-hfr4-8rjc-97m2; retrieved 2026-11-10; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-126085; retrieved 2026-11-14; source updated Not reported

Revision: fa9ab8991fadc93c7751d92d289e1b161712aecc00e362844a80f6a8512d2ccc

Canonical: https://y2.dev/cve/CVE-2026-126085

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