What is CVE-2026-125040?

CVE-2026-125040 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Inefficient Regular Expression Complexity. CVSS score: 6.5/10. Published 2026-11-09.

How severe is CVE-2026-125040?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Red Hat Enterprise Linux 10

CVE-2026-125040

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.

Vulnerability class: ReDoS (Regular Expression Denial of Service)

Published 2026-11-09 · last modified 2026-11-09.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-1333 — Inefficient Regular Expression Complexity

References

access.redhat.com/security/cve/CVE-2026-125040 (vdb-entry)
bugzilla.redhat.com/show_bug.cgi (issue-tracking)
gstreamer.freedesktop.org/security/sa-2026-0023.html

Frequently asked questions

What is CVE-2026-125040?: CVE-2026-125040 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Inefficient Regular Expression Complexity. CVSS score: 6.5/10. Published 2026-11-09.
How severe is CVE-2026-125040?: Medium severity. CVSS v3 base score is 6.5 out of 10.