Action Pack is a framework for handling and responding to web requests. In versions prior to 7.2.3.2, 8.0.5.1 and 8.1.3.1, Active Storage does not disable libvips operations marked unsafe for untrusted content, allowing a crafted upload to invoke such an operation. Consuming applications are affected when configured to use libvips and accept image uploads from untrusted users. An unauthenticated attacker may exploit this behavior to read arbitrary files accessible to the Rails process, including environment variables and application secrets. Exposure of credentials such as secret_key_base or external-service tokens may enable remote code execution or lateral movement. This issue has been fixed in versions 7.2.3.2, 8.0.5.1 and 8.1.3.1.

Researchers disclosed "KindaRails2Shell" a remote code execution in Ruby on Rails Active Storage. No PoC yet but we're monitoring. Upgrade Rails and libvips ASAP.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4829 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4829-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                        Simon Quigley     October 08, 2026                              https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : rails     Version        : 2:6.1.7.10+dfsg-1~deb12u3     CVE ID         : CVE-2026-33168 CVE-2026-33169 CVE-2026-33170 CVE-2026-33173                      CVE-2026-33176 CVE-2026-33195 CVE-2026-33202 CVE-2026-66066     Debian Bug     : 1132035 1143080

    Multiple security issues were discovered in the Rails web framework     which could result in cross-site scripting, denial of service, path     traversal, or the execution of arbitrary code.

    CVE-2026-33168

        In Action View, tag helpers skipped escaping when an HTML attribute         name was blank, which could allow cross-site scripting. Blank         attribute names are now dropped.

    CVE-2026-33169

        In Active Support, number_to_delimited took quadratic time on long         digit strings, which could be used for a denial of service.

    CVE-2026-33170

        In Active Support, formatting an unsafe SafeBuffer with % marked         the result as html_safe, which could allow cross-site scripting.
        The result now stays unsafe.

    CVE-2026-33173

        In Active Storage, a direct upload could set the analyzed and         identified metadata keys and skip content-type detection. Those         keys are now dropped from client-supplied metadata.

    CVE-2026-33176

        In Action View, number helpers expanded scientific notation through         BigDecimal, so input such as 1E1000 could use excessive CPU and         memory, leading to a denial of service.

    CVE-2026-33195

        In Active Storage, the disk service accepted keys containing ../,         which allowed path traversal outside the storage root. Such keys now         raise InvalidKeyError.

    CVE-2026-33202

        In Active Storage, the disk service's delete_prefixed passed the         prefix to Dir.glob without escaping, so glob metacharacters could         delete unintended files. Glob metacharacters are now escaped.

    CVE-2026-66066

        In Active Storage, applications that set the variant processor to         :vips left libvips's untrusted, unfuzzed loaders enabled, which could         allow crafted images to execute arbitrary code. The vips processor         now blocks untrusted loaders. The default MiniMagick processor is         not affected.

    For Debian 12 bookworm, these problems have been fixed in version     2:6.1.7.10+dfsg-1~deb12u3.

    We recommend that you upgrade your rails packages.

    For the detailed security status of rails please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/rails

    Further information about Debian LTS security advisories, how to apply     these updates to your system, and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6546 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6546-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     October 06, 2026                      https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : rails     CVE ID         : CVE-2026-33168 CVE-2026-33169 CVE-2026-33170 CVE-2026-33173                      CVE-2026-33174 CVE-2026-33176 CVE-2026-33195 CVE-2026-33202                      CVE-2026-33658 CVE-2026-66066

    Multiple security issues were discovered in the Rails web framework     which could result in cross-site scripting, denial of service, path     traversal or the execution of arbitrary code.

    For the stable distribution (trixie), these problems have been fixed in     version 2:7.2.2.2+dfsg-2~deb13u2.

    We recommend that you upgrade your rails packages.

    For the detailed security status of rails please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/rails

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Action Pack is a framework for handling and responding to web requests. In versions prior to 7.2.3.2,
    8.0.5.1 and 8.1.3.1, Active Storage does not disable libvips operations marked unsafe for untrusted
    content, allowing a crafted upload to invoke such an operation. Consuming applications are affected when
    configured to use libvips and accept image uploads from untrusted users. An unauthenticated attacker may
    exploit this behavior to read arbitrary files accessible to the Rails process, including environment
    variables and application secrets. Exposure of credentials such as secret_key_base or external-service
    tokens may enable remote code execution or lateral movement. This issue has been fixed in versions
    7.2.3.2, 8.0.5.1 and 8.1.3.1. (CVE-2026-66066)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Action Pack is a framework for handling and responding to web requests. In versions prior to 7.2.3.2,     8.0.5.1 and 8.1.3.1, Active Storage does not disable libvips operations marked unsafe for untrusted     content, allowing a crafted upload to invoke such an operation. Consuming applications are affected when     configured to use libvips and accept image uploads from untrusted users. An unauthenticated attacker may     exploit this behavior to read arbitrary files accessible to the Rails process, including environment     variables and application secrets. Exposure of credentials such as secret_key_base or external-service     tokens may enable remote code execution or lateral movement. This issue has been fixed in versions     7.2.3.2, 8.0.5.1 and 8.1.3.1. (CVE-2026-66066)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
364213	Debian dla-4829 : rails - security update	Nessus	Debian Local Security Checks	Local	critical
363441	Debian dsa-6546 : rails - security update	Nessus	Debian Local Security Checks	Local	critical
445492	SCA: security update for activestorage (GHSA-xr9x-r78c-5hrm)	Tenable Cloud Security	SCA Checks	Local	critical
445492	SCA: security update for activestorage (GHSA-xr9x-r78c-5hrm)	Tenable Self-Hosted Container Security	SCA Checks	Local	critical
331117	Linux Distros Unpatched Vulnerability : CVE-2026-66066	Nessus	Misc.	Local	critical

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CVE-2026-66066

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