CVE-2026-75146
Description
A flaw was found in FFmpeg. A malicious or misconfigured DASH (Dynamic Adaptive Streaming over HTTP) server can exploit an out-of-bounds read vulnerability in the DASH demuxer. This occurs when a live DASH manifest is refreshed with a startNumber that is lower than the previous value, causing a negative index to be used in the fragment retrieval function. Successful exploitation could lead to information disclosure or a denial of service.
Statement
The ffmpeg package is not shipped in base Red Hat Enterprise Linux. It is available through EPEL, Red Hat Enterprise Linux AI, and as a bundled dependency in Red Hat OpenShift AI container images. The vulnerable code resides in the DASH demuxer (libavformat/dashdec.c), which is compiled and shipped in all FFmpeg builds across these products. Exploitation requires a malicious or misconfigured DASH server to serve a live manifest with a decreasing startNumber across a refresh.
Mitigation
No mitigation is currently available for this flaw.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | N/A | 8.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
Acknowledgements
Upstream acknowledges Joshua Rogers (AISLE Research) as the original reporter.
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