Memory corruption via unchecked BCn encoder writes
Published Jul 1, 2025 · Updated Jul 1, 2025
Heap buffer overflow in Pillow 11.2.0 through 11.2.1 allows local users to corrupt memory by saving a large compressed DDS image. ImagingBcnEncode in src/libImaging/BcnEncode.c writes up to 16 encoded bytes per loop iteration without first verifying that the destination buffer has enough space. The flaw is reached only when an application saves untrusted image data as compressed DDS and can abort the process with heap corruption.
Summary
What happened
Heap buffer overflow in Pillow 11.2.0 through 11.2.1 allows local users to corrupt memory by saving a large compressed DDS image. ImagingBcnEncode in src/libImaging/BcnEncode.c writes up to 16 encoded bytes per loop iteration without first verifying that the destination buffer has enough space. The flaw is reached only when an application saves untrusted image data as compressed DDS and can abort the process with heap corruption.
The record
- CVE
- CVE-2025-48379
- Published
- Jul 1, 2025
- Updated
- Jul 1, 2025
- Vendor
- Pillow
- Product
- Pillow
- Classifications
- CWE-122
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 1, 2025CVE publishedPublication date reported by the CVE source.
- Jul 1, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 11.2.0, < 11.3.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Compressed DDS BCn crash reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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