VDB-382390 · CVE-2026-64834 · GCVE-0-2026-64834

FFmpeg up to 8.1.2 ASF Demuxer libavformat/rtpdec_asf.c rtp_asf_fix_header infinite loop

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in FFmpeg up to 8.1.2. This affects the function rtp_asf_fix_header of the file libavformat/rtpdec_asf.c of the component ASF Demuxer. Executing a manipulation can lead to infinite loop. This vulnerability is registered as CVE-2026-64834. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in FFmpeg up to 8.1.2. It has been declared as problematic. This vulnerability affects the function rtp_asf_fix_header of the file libavformat/rtpdec_asf.c of the component ASF Demuxer. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect availability. CVE summarizes:

FFmpeg versions 0.6.3 through 8.1.2 contain an infinite loop vulnerability in the RTP/ASF demuxer within libavformat/rtpdec_asf.c that allows remote attackers to cause denial of service by sending a crafted RTP/ASF stream. The rtp_asf_fix_header function fails to validate a minimum chunksize when iterating over ASF objects, causing the loop pointer to never advance when a chunksize is smaller than the 24-byte minimum ASF object header size, resulting in CPU exhaustion that denies service to legitimate users.

The advisory is available at code.ffmpeg.org. This vulnerability was named CVE-2026-64834 since 07/20/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

Multimedia Processing Software

Name

FFmpeg

Version

License

open-source

Website

Product: https://ffmpeg.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

07/20/2026 CVE reserved
07/22/2026 +2 days Advisory disclosed
07/22/2026 +0 days VulDB entry created
07/22/2026 +0 days VulDB entry last update

Sourcesinfo

Product: ffmpeg.org

Advisory: code.ffmpeg.org
Status: Not defined

CVE: CVE-2026-64834 (🔒)
GCVE (CVE): GCVE-0-2026-64834
GCVE (VulDB): GCVE-100-382390

Entryinfo

Created: 07/22/2026 19:48
Changes: 07/22/2026 19:48 (54)
Complete: 🔍
Cache ID: 216::103