CVE-2023-6604Public exploitNetwork attack vector

Resource exhaustion via unchecked XBIN segment probing

Published Jan 6, 2025 · Updated Nov 3, 2025

Denial of service in the HLS demuxer in FFmpeg 2.0 through 6.0 allows remote attackers to exhaust CPU and storage. When input format is not enforced, libavformat/hls.c allows mismatched segment extensions to retain the XBIN demuxer, so an 11-byte XBIN header makes arbitrary following bytes decode as character-and-color pairs. A crafted playlist can turn a 16 MB input into a 352 MB, 43-minute output, consuming transcoding time and disk capacity without authentication.

CVSS severity5.3
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the HLS demuxer in FFmpeg 2.0 through 6.0 allows remote attackers to exhaust CPU and storage. When input format is not enforced, libavformat/hls.c allows mismatched segment extensions to retain the XBIN demuxer, so an 11-byte XBIN header makes arbitrary following bytes decode as character-and-color pairs. A crafted playlist can turn a 16 MB input into a 352 MB, 43-minute output, consuming transcoding time and disk capacity without authentication.

The record

CVE
CVE-2023-6604
Published
Jan 6, 2025
Updated
Nov 3, 2025
Vendor
FFmpeg
Product
FFmpeg
Classifications
CWE-99, CWE-94, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 6, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.0 <6.*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FFmpeg · FFmpegversion=2.0 <6.*

Published CVSS scores

5.3Fedora ProjectCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-99Improper Control of Resource Identifiers ('Resource Injection')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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