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CVE-2026-125040Red Hat Enterprise Linux 10 regular expression denial of service

Low priorityMedium6.5EPSS not scored yet

CVE-2026-125040 is a regular expression denial of service in Red Hat Enterprise Linux 10, rated medium (6.5 on CVSS 3.1).

Why this priority: Medium severity, with no exploitation signal.

Published · Updated · NVD status: Awaiting Analysis

What it is

A crafted string makes a regular expression run for a very long time.

How it is reached

An attacker can exploit it over the network, without an account, but someone has to act first, such as opening a file or following a link.

What an attacker gains

A successful attack can take it offline. 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

  1. No fixed version is listed yet. Find every place Red Hat Enterprise Linux 10 runs, watch the references for a fix, and plan a replacement if it is no longer supported.
  2. While there is no fix, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
  3. Warn the people who use it, and filter files and links on the way in.

Description from NVD

A flaw was found in the SRT and WebVTT subtitle parser in GStreamer's gst-plugins-base. While sanitizing inline subtitle markup, the parser repeatedly searches the remaining text with unanchored regular expressions. A crafted subtitle cue with a long line of unmatched markup-like text can force quadratic CPU use and make a GStreamer-based application unresponsive.

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

  • Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
  • People who open files and links. Mail, chat and browsers are the delivery path.
  • 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 Red Hat Enterprise Linux 10 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?

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.