HomeCVE Intelligence › CVE-2026-59197
CVSS 8.2 HIGH Vulnerability

CVE-2026-59197: Pillow: Heap out-of-bounds write in `ImageFilter.RankFilter` via integer overflow in `Ima…

Summary Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size. Minimal public API trigger: ``python from PIL import Image, ImageFilter im = Image.new("L",…

8.2CVSS Score
HIGHSeverity
NOCISA KEV
0.4%EPSS Score
VulnerabilityImpact Type

📋 Vulnerability Details

CVE IDCVE-2026-59197
Vendorpip
Affected ProductPillow
Vulnerability TypeVulnerability
CVSS Score8.2 (HIGH)
EPSS Score0.4% probability of exploitation in the next 30 days
Actively Exploited❌ No known exploitation
Patch StatusSee Vendor Advisory →
Reported ByCYBERDUDEBIVASH SENTINEL APEX Intelligence (via github_advisories)

🔬 Technical Analysis

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Summary Pillow's public rank-filter API can trigger a native heap out-of-bounds write

when given a very large odd filter size. Minimal public API trigger: ``python from PIL import Image, ImageFilter im = Image.new("L", (3, 3), 128) im.filter(ImageFilter.MedianFilter(4294967295)) ` ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation. With size = 4294967295, the expansion margin is 2147483647 (INT_MAX). ImagingExpand() then computes the output dimensions with unchecked signed int arithmetic. On tested builds, this wraps to a tiny output image and the border-expansion loop writes past the allocation. This is reachable through documented public classes (RankFilter, MedianFilter, MinFilter, and MaxFilter`). No p

📚 Advisory References

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