CVE-2026-126074rails uncaught exception
CVE-2026-126074 is a uncaught exception in rails, rated medium (4.3 on CVSS 3.1).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Received
What it is
An error nobody catches stops the process or request.
How it is reached
An attacker can exploit it over the network, with an ordinary user account, and nobody has to click anything.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker exhaust CPU, memory or connections until the service stops answering.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade rails to a fixed version for your release line (8.1.4.1, 8.0.5.2).
- Until it is patched, review who holds accounts that can reach it.
Description from NVD
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::Filename#base and #extension_with_delimiter, and therefore #extension, pass the stored filename unmodified to File.basename and File.extname, which raise ArgumentError when the name contains a NUL byte. Active Storage stores the client-supplied filename verbatim, so a user who is permitted to upload an attachment could persist such a filename on databases that accept NUL bytes in string columns, such as SQLite and MySQL/MariaDB. Each subsequent request that builds a variant or preview of the blob, opens it, or renders it as an Action Text attachment then raises, possibly resulting in a persistent DoS vulnerability for the pages that display the blob until it is purged or its filename is corrected. Applications that use PostgreSQL are not affected, because PostgreSQL rejects the row. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Public entry points and shared services that must stay up. The flaw sits between untrusted traffic and shared capacity.
Trust boundaries in play
- Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
- Between untrusted traffic and shared capacity. An attacker who crosses it can exhaust CPU, memory or connections until the service stops answering.
Questions to answer about your own systems
- Where does rails run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Patches and commits
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.