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CVE-2026-33173

CVE-2026-33173 · Rails Active Storage has possible content type bypass via metadata in direct uploads

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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, `DirectUploadsController` accepts arbitrary metadata from the client and persists it on the blob. Because internal flags like `identified` and `analyzed` are stored in the same metadata hash, a direct-upload client can set these flags to skip MIME detection and analysis. This allows an attacker to upload arbitrary content while claiming a safe `content_type`, bypassing any validations that rely on Active Storage's automatic content type identification. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

CVSS 5.3 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • activestorage

    Versions
    • >= 8.1.0.beta1, < 8.1.2.1: Affected
    • >= 8.0.0.beta1, < 8.0.4.1: Affected
    • < 7.2.3.1: Affected

    No fix published

  • rails Debian:12

    Versions
    • 2:6.1.7.10+dfsg-1~deb12u1
    • 2:6.1.7.10+dfsg-1~deb12u2
    • 2:6.1.7.3+dfsg-1
    • 2:6.1.7.3+dfsg-10
    • 2:6.1.7.3+dfsg-11
    • 2:6.1.7.3+dfsg-12
    • 2:6.1.7.3+dfsg-13
    • 2:6.1.7.3+dfsg-2
    • 2:6.1.7.3+dfsg-2~deb12u1
    • 2:6.1.7.3+dfsg-3
    • 2:6.1.7.3+dfsg-4
    • 2:6.1.7.3+dfsg-5
    • 2:6.1.7.3+dfsg-6
    • 2:6.1.7.3+dfsg-7
    • 2:6.1.7.3+dfsg-7~exp1
    • 2:6.1.7.3+dfsg-8
    • 2:6.1.7.3+dfsg-9
    Affected ranges
    • ECOSYSTEM: < 2:6.1.7.10+dfsg-1~deb12u3

    Update to 2:6.1.7.10+dfsg-1~deb12u3

  • rails Debian:13

    Versions
    • 2:7.2.2.1+dfsg-7
    • 2:7.2.2.2+dfsg-1
    • 2:7.2.2.2+dfsg-2~deb13u1
    Affected ranges
    • ECOSYSTEM: < 2:7.2.2.2+dfsg-2~deb13u2

    Update to 2:7.2.2.2+dfsg-2~deb13u2

  • rails Debian:14

    Versions
    • 2:7.2.2.1+dfsg-7
    • 2:7.2.2.2+dfsg-1
    • 2:7.2.2.2+dfsg-2
    • 2:7.2.2.2+dfsg-2~deb13u1
    • 2:7.2.2.2+dfsg-2~deb13u2
    • 2:7.2.3+dfsg-1
    • 2:7.2.3+dfsg-2
    • 2:7.2.3+dfsg-3
    Affected ranges
    • ECOSYSTEM: < 2:7.2.3.1+dfsg-1

    Update to 2:7.2.3.1+dfsg-1

  • rails Ubuntu:Pro:16.04:LTS

    Versions
    • 2:4.1.10-1
    • 2:4.2.5-1
    • 2:4.2.5.1-1
    • 2:4.2.5.2-2
    • 2:4.2.6-1
    • 2:4.2.6-1ubuntu0.1~esm1
    • 2:4.2.6-1ubuntu0.1~esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:Pro:18.04:LTS

    Versions
    • 2:4.2.9-2
    • 2:4.2.9-4
    • 2:4.2.10-0ubuntu4
    • 2:4.2.10-0ubuntu4+esm1
    • 2:4.2.10-0ubuntu4+esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:Pro:20.04:LTS

    Versions
    • 2:5.2.2.1+dfsg-1ubuntu1
    • 2:5.2.3+dfsg-3
    • 2:5.2.3+dfsg-3ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:Pro:22.04:LTS

    Versions
    • 2:6.0.3.7+dfsg-2
    • 2:6.1.4.1+dfsg-8ubuntu2
    • 2:6.1.4.1+dfsg-8ubuntu2+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:24.04:LTS

    Versions
    • 2:6.1.7.3+dfsg-2build1
    • 2:6.1.7.3+dfsg-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:25.10

    Versions
    • 2:6.1.7.3+dfsg-7
    • 2:7.2.2.1+dfsg-7
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:26.10

    Versions
    • 2:7.2.3+dfsg-2
    • 2:7.2.3.2+dfsg-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • rails Ubuntu:26.04:LTS

    Versions
    • 2:7.2.2.1+dfsg-7
    • 2:7.2.2.2+dfsg-2
    • 2:7.2.3+dfsg-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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