Pillow up to 12.x RLE Decoder BmpImagePlugin.py BmpRleDecoder.decode denial of service

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k4.52

Summaryinfo

A vulnerability classified as problematic has been found in Pillow up to 12.x. Affected by this issue is the function BmpRleDecoder.decode of the file src/PIL/BmpImagePlugin.py of the component RLE Decoder. The manipulation leads to denial of service. This vulnerability is uniquely identified as CVE-2026-96638. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Pillow up to 12.x. It has been rated as problematic. This issue affects the function BmpRleDecoder.decode of the file src/PIL/BmpImagePlugin.py of the component RLE Decoder. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

Pillow is a Python imaging library. From 9.1.0 until 13.0.0, BmpRleDecoder.decode() in src/PIL/BmpImagePlugin.py permits crafted RLE BMP delta escapes and absolute-mode runs to append beyond the remaining dest_length without a per-branch cap. A delta can add roughly 255 image rows in one iteration, so a kilobyte-sized file with a large but permitted width can expand the data bytearray to hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-96638 since 09/23/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 13.0.0 eliminates this vulnerability.

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Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
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: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Pillow 13.0.0

Timelineinfo

09/23/2026 CVE reserved
10/21/2026 +28 days Advisory disclosed
10/21/2026 +0 days VulDB entry created
10/21/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-96638 (🔒)
GCVE (CVE): GCVE-0-2026-96638
GCVE (VulDB): GCVE-100-424997

Entryinfo

Created: 10/21/2026 23:02
Changes: 10/21/2026 23:02 (65)
Complete: 🔍
Cache ID: 216::103

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