CVE-2026-75146Network attack vector

Out-of-bounds read via negative fragment index

Published Aug 19, 2026 · Updated Aug 20, 2026

Out-of-bounds read in the DASH demuxer in FFmpeg before commit 65b0dab allows remote attackers to read process memory via live manifest refreshes. In libavformat/dashdec.c, a refreshed live manifest can lower startNumber, drive cur_seq_no below zero, and reach fragment retrieval logic that indexed the fragments array after checking only the upper bound. Exposure requires processing a live DASH stream from a malicious or misconfigured server, and the practical consequence is bounded to memory disclosure or a crash rather than data modification.

CVSS severity8.1
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the DASH demuxer in FFmpeg before commit 65b0dab allows remote attackers to read process memory via live manifest refreshes. In libavformat/dashdec.c, a refreshed live manifest can lower startNumber, drive cur_seq_no below zero, and reach fragment retrieval logic that indexed the fragments array after checking only the upper bound. Exposure requires processing a live DASH stream from a malicious or misconfigured server, and the practical consequence is bounded to memory disclosure or a crash rather than data modification.

The record

CVE
CVE-2026-75146
Published
Aug 19, 2026
Updated
Aug 20, 2026
Vendor
FFmpeg
Product
FFmpeg
Classifications
CWE-125
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=0 <65b0dab903e5975e036b30ecc58f5935d4f151e0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FFmpeg · FFmpegversion=0 <65b0dab903e5975e036b30ecc58f5935d4f151e0

Published CVSS scores

7.2VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
8.1VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

Public exploit references

No public exploit references are available in this record.

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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