Code execution via overflowed PSD tile extents
Published May 9, 2026 · Updated May 9, 2026
Out-of-bounds write in Pillow 10.3.0 through 12.1.1 allows attackers to crash processes or execute code via a malicious PSD file. PSD tile bounds checks in src/decode.c and src/encode.c add attacker-controlled extents in overflow-prone integer types, so wrapped sums bypass range validation and drive an out-of-bounds write. Reachability requires an application to decode or encode an attacker-supplied PSD; successful exploitation corrupts process memory and can terminate the process or execute code in its security context.
Summary
What happened
Out-of-bounds write in Pillow 10.3.0 through 12.1.1 allows attackers to crash processes or execute code via a malicious PSD file. PSD tile bounds checks in src/decode.c and src/encode.c add attacker-controlled extents in overflow-prone integer types, so wrapped sums bypass range validation and drive an out-of-bounds write. Reachability requires an application to decode or encode an attacker-supplied PSD; successful exploitation corrupts process memory and can terminate the process or execute code in its security context.
The record
- CVE
- CVE-2026-42311
- Published
- May 9, 2026
- Updated
- May 9, 2026
- Vendor
- Pillow
- Product
- Pillow
- Classifications
- CWE-190, CWE-787, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 9, 2026CVE publishedPublication date reported by the CVE source.
- May 9, 2026Record 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=>= 10.3.0, < 12.2.0
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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