---
id: "CVE-2026-125040"
page: "https://infrastack.ai/live/CVE-2026-125040"
kind: "vulnerability"
aliases: ["CVE-2026-125040"]
title: "GStreamer: crafted subtitle cues can freeze media apps via CPU exhaustion"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "runtime"
products: [{"name": "gst-plugins-base", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["gst-plugins-base", "gstreamer", "media-processing", "runtime", "self-hosted"]
not_affected_if: ["no-untrusted-subtitles", "subtitle-parsing-unused"]
published_at: "2026-11-09T19:16:48+00:00"
first_seen_at: "2026-11-09T19:28:14+00:00"
updated_at: "2026-11-09T19:31:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125040", "first_seen_at": "2026-11-09T19:28:14+00:00"}]
exploit_sources: []
---

# GStreamer: crafted subtitle cues can freeze media apps via CPU exhaustion

Link for people: https://infrastack.ai/live/CVE-2026-125040 (this .md is for agents)

The SRT and WebVTT subtitle parser in GStreamer's gst-plugins-base uses unanchored regular expressions while sanitizing inline markup, so a long line of unmatched markup-like text makes CPU use grow quadratically. An attacker who supplies a crafted subtitle cue can make a GStreamer-based application unresponsive.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:gst-plugins-base affected range not listed fixed no fixed version listed

## Timeline

- 2026-11-09T19:28:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125040

## From the sources

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.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_