FFmpeg up to 9.0.2 DVB Subtitle Encoder libavcodec/dvbsubenc.c dvbsub_encode heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00+

Summaryinfo

A vulnerability labeled as problematic has been found in FFmpeg up to 9.0.2. The impacted element is the function dvbsub_encode of the file libavcodec/dvbsubenc.c of the component DVB Subtitle Encoder. Such manipulation leads to heap-based overflow. This vulnerability is uniquely identified as CVE-2026-125233. Local access is required to approach this attack. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in FFmpeg up to 9.0.2. Affected by this issue is the function dvbsub_encode of the file libavcodec/dvbsubenc.c of the component DVB Subtitle Encoder. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. The product writes past the end of a buffer that was allocated on the heap. Impacted is confidentiality, integrity, and availability. CVE summarizes:

FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in dvbsub_encode() in libavcodec/dvbsubenc.c that undercounts each CLUT segment header by two bytes. Attackers can supply a file with many bitmap subtitle rectangles that, when transcoded to the dvbsub encoder, writes past the output buffer and corrupts heap memory.

The advisory is shared for download at code.ffmpeg.org. This vulnerability is handled as CVE-2026-125233 since 11/09/2026. The exploitation is known to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/09/2026).

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

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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: 6.3
VulDB Meta Temp Score: 6.3

VulDB Base Score: 4.8
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (VulnCheck): 🔒

CVSSv2info

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

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

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-2026-125233 (🔒)

GCVE (CVE): GCVE-0-2026-125233
GCVE (VulDB): GCVE-100-433352

Entryinfo

Created: 11/09/2026 20:53
Changes: 11/09/2026 20:53 (75)
Complete: 🔍
Cache ID: 216::103

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