Performance Degradation in GStreamer's Subtitle Parser
CVE-2026-125040

6.5MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 9
Vendor
CVE Published:
9 November 2026

What is CVE-2026-125040?

A vulnerability exists in GStreamer's SRT and WebVTT subtitle parser, where improper sanitization of inline subtitle markup can lead to excessive CPU usage. When a crafted subtitle cue with an extensive line of unmatched markup-like text is processed, the parser executes repeated searches with unanchored regular expressions. This behavior can cause a GStreamer-based application to become unresponsive, severely impacting performance.

References

https://access.redhat.com/security/cve/CVE-2026-125040
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2569124
issue-trackingx_refsource_REDHAT
https://gstreamer.freedesktop.org/security/sa-2026-0023.html

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.