Description
ImageSharp is a 2D graphics library. From 2.0.0 until 4.1.2, the TIFF CCITT Group 3 encoder allocates an undersized compressed-data buffer for narrow 1-bit images. TiffCcittCompressor.Initialize does not reserve enough space for the row data and T4 end-of-line codes, and T4BitCompressor.CompressStrip reaches unchecked writes when TiffCompression.CcittGroup3Fax is selected directly or inherited from decoded TIFF metadata. An attacker-controlled encode or decode-and-re-encode flow can write beyond the logical output span, corrupt process memory, and terminate the process. This issue is fixed in version 4.1.2.
Affected products
sixlabors: imagesharp
References5
- github.com/SixLabors/ImageSharp/security/advisories/GHSA-j9gm-c… ExploitVendor Advisory
- github.com/SixLabors/ImageSharp/security/advisories/GHSA-j9gm-c… ExploitVendor Advisory
- github.com/SixLabors/ImageSharp/commit/a9498c6db3642ef92c712ebc… Patch
- github.com/SixLabors/ImageSharp/pull/3187 Issue TrackingPatch
- github.com/SixLabors/ImageSharp/releases/tag/v4.1.2 Release Notes
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 33 · as of 10 November 2026
- CWE
- CWE-787
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