CVE-2026-125040 vulnerability in Red Hat Products
Published on November 9, 2026
Gst-plugins-base: gst-plugins-base: quadratic regex processing in srt/webvtt subtitle parser causes denial of service
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 Analysis
CVE-2026-125040 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is a ReDoS Vulnerability?
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles. Some regular expression engines have a feature called "backtracking". If the token cannot match, the engine "backtracks" to a position that may result in a different token that can match. Backtracking becomes a weakness if all of these conditions are met:
CVE-2026-125040 has been classified to as a ReDoS vulnerability or weakness.
Products Associated with CVE-2026-125040
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