Stale buffer data disclosure in ImageSharp EXR ZIP decoding
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
ImageSharp from 4.0.0 before 4.1.2 (NuGet package SixLabors.ImageSharp) has a flaw in its EXR ZIP decompression, where CWE-226 applies because the code does not clear reused memory. The decoder accepts a ZIP or ZIPS inflate result shorter than the block size, so bytes left in a reused buffer from an earlier ImageSharp operation can appear in decoded pixels. An unauthenticated remote attacker who supplies a crafted EXR file can disclose process-local image data in applications that expose the decoded output. A public exploit is linked in the references.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
ImageSharp is a 2D graphics library. From 4.0.0 until 4.1.2, ExrBaseDecompressor.UndoZipCompression accepts a nonempty ZIP or ZIPS inflate result that is shorter than the EXR block's required size. ZipExrCompression.Decompress reconstructs the returned prefix while ExrDecoderCore processes the full expected block from a buffer obtained through Configuration.Default, allowing bytes retained from a completed prior ImageSharp operation to appear in decoded pixels. Applications that expose pixels or output from the later attacker-controlled EXR decode can disclose process-local image data. This issue is fixed in version 4.1.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| SixLabors | ImageSharp | 4.0.0 to before 4.1.2 | 4.1.2 | Patch available | CNA |
| — | SixLabors.ImageSharp (NuGet) | 4.0.0 to before 4.1.2 | 4.1.2 | Patch available | GHSA-4q3p-rj5x-xv7p |
- ImageSharp VendorSixLabors Affected 4.0.0 to before 4.1.2 Fixed in 4.1.2 Patch available CNA
- SixLabors.ImageSharp (NuGet) Vendor— Affected 4.0.0 to before 4.1.2 Fixed in 4.1.2 Patch available GHSA-4q3p-rj5x-xv7p
Remediation
Upgrade the SixLabors.ImageSharp NuGet package to version 4.1.2, which fixes this issue. Versions from 4.0.0 before 4.1.2 are affected.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA ImageSharp (SixLabors) Fixed in 4.1.2
- Fix · GHSA-4q3p-rj5x-xv7p SixLabors.ImageSharp (NuGet) Fixed in 4.1.2 Advisory →
Timeline
- 2026-10-06 Threatist record created from CVE-2026-106111
- 2026-10-07 Alias added: GHSA-4q3p-rj5x-xv7p
- 2026-10-07 Fix available: NuGet/[email protected] · GHSA-4q3p-rj5x-xv7p
- 2026-10-07 CVSS score added · GHSA-4q3p-rj5x-xv7p
- 2026-10-07 Weakness changed · GHSA-4q3p-rj5x-xv7p
- 2026-10-07 7 new references · GHSA-4q3p-rj5x-xv7p
- 2026-10-24 CVSS score added · NVD
References
Patch 3
More SixLabors Imagesharp vulnerabilities
- TI-2026-68636 Out-of-bounds write in ImageSharp CCITT fax decompression CVSS 3.1HIGH 7.5
- TI-2026-68634 Out-of-bounds write in ImageSharp TIFF CCITT Group 4 encoder CVSS 3.1HIGH 7.5
- TI-2026-68629 Out-of-bounds write in ImageSharp TIFF CCITT encoder CVSS 3.1HIGH 7.5
- TI-2025-20408 Out-of-bounds Write in SixLabors ImageSharp CVSS 3.1HIGH 7.5
- TI-2026-68635 ImageSharp BigTIFF IFD count can keep a decoder thread in a non-progressing loop CVSS 3.1MEDIUM 5.3
- TI-2026-68633 Excessive memory allocation in ImageSharp ICC CLUT parsing CVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-106111 · CVE Program
- CVE-2026-106111 · NVD
- FIRST EPSS
- GHSA-4q3p-rj5x-xv7p · GitHub Advisory Database · CC BY 4.0
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