FFmpeg up to 9.0.2 FLAC Parser libavcodec/flac_parser.c score_header recursion

CVSS Meta Temp Score
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CTI Interest Score
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4.9$0-$5k0.00+

Summaryinfo

A vulnerability was found in FFmpeg up to 9.0.2 and classified as problematic. The affected element is the function score_header of the file libavcodec/flac_parser.c of the component FLAC Parser. Executing a manipulation can lead to recursion. This vulnerability appears as CVE-2026-125221. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in FFmpeg up to 9.0.2 and classified as problematic. This vulnerability affects the function score_header of the file libavcodec/flac_parser.c of the component FLAC Parser. The manipulation with an unknown input leads to a recursion vulnerability. The CWE definition for the vulnerability is CWE-674. The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. As an impact it is known to affect availability. CVE summarizes:

FFmpeg through 9.0.2 contains an uncontrolled recursion vulnerability in score_header() in libavcodec/flac_parser.c that allows attackers to exhaust the thread stack via crafted FLAC input. Attackers can supply a FLAC stream packed with many small valid-looking frame headers, forcing deep recursion that crashes the process during demuxing or parsing.

The advisory is available at code.ffmpeg.org. This vulnerability was named CVE-2026-125221 since 11/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. 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

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.3
VulDB Temp Score: 4.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Recursion
CWE: CWE-674 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

11/09/2026 Advisory disclosed
11/09/2026 +0 days CVE reserved
11/09/2026 +0 days VulDB entry created
11/09/2026 +0 days VulDB entry last update

Sourcesinfo

Product: ffmpeg.org

Advisory: code.ffmpeg.org
Status: Not defined

CNA: VulnCheck
CVE: CVE-2026-125221 (🔒)

GCVE (CVE): GCVE-0-2026-125221
GCVE (VulDB): GCVE-100-433318

Entryinfo

Created: 11/09/2026 20:42
Changes: 11/09/2026 20:42 (75)
Complete: 🔍
Cache ID: 216::103

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