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TI-2026-68637 Aliases CVE-2026-106118GHSA-v76p-62qx-wwq2

Out-of-bounds write in ImageSharp tiled fax TIFF decoding

Priority MEDIUM 40CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-787 and the CVSS impact.

Summary

ImageSharp from 3.0.0 before 4.1.1 is affected. Tiled TIFF decoding sizes the destination buffer by tile width but decodes T4, T6 and Modified Huffman fax data at full image width, causing an out-of-bounds heap write (CWE-787). A remote attacker can corrupt the heap and terminate the process by supplying a crafted tiled TIFF image, without privileges or user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

ImageSharp is a 2D graphics library. From 3.0.0 until 4.1.1, tiled TIFF decoding allocates a destination buffer using TileWidth but TiffDecompressorsFactory.Create constructs T4, T6, and Modified Huffman decompressors using the full frame width. TiffDecoderCore.DecodeTilesChunky can therefore direct frame-width fax scanlines into a tile-width buffer when TileWidth is smaller than ImageWidth. The mismatch causes attacker-controlled out-of-bounds writes, heap corruption, and process termination even with legal per-row run codes. This tiled-path vulnerability is distinct from oversized CCITT runs in strip decoding. This issue is fixed in version 4.1.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00595 48th percentileScored 2026-11-07
Fix Fixed ImageSharp (SixLabors): 4.1.1SixLabors.ImageSharp (NuGet): 3.2.0, 4.1.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
SixLaborsImageSharp3.0.0 to before 4.1.14.1.1Patch availableCNA
—SixLabors.ImageSharp (NuGet)3.0.0 to before 3.2.03.2.0Patch availableGHSA-v76p-62qx-wwq2
—SixLabors.ImageSharp (NuGet)4.0.0 to before 4.1.14.1.1Patch availableGHSA-v76p-62qx-wwq2
  • ImageSharp VendorSixLabors Affected 3.0.0 to before 4.1.1 Fixed in 4.1.1 Patch available CNA
  • SixLabors.ImageSharp (NuGet) Vendor— Affected 3.0.0 to before 3.2.0 Fixed in 3.2.0 Patch available GHSA-v76p-62qx-wwq2
  • SixLabors.ImageSharp (NuGet) Vendor— Affected 4.0.0 to before 4.1.1 Fixed in 4.1.1 Patch available GHSA-v76p-62qx-wwq2

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:sixlabors:imagesharp:*:*:*:*:*:*:*:*——SixLabors
  • cpe:2.3:a:sixlabors:imagesharp:*:*:*:*:*:*:*:* Versions — — ·SixLabors

Remediation

Fixed versions are 3.2.0 for the SixLabors.ImageSharp NuGet 3.x line and 4.1.1 for the SixLabors.ImageSharp NuGet 4.x line.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA ImageSharp (SixLabors) Fixed in 4.1.1
  • Fix · GHSA-v76p-62qx-wwq2 SixLabors.ImageSharp (NuGet) Fixed in 3.2.0 Advisory →
  • Fix · GHSA-v76p-62qx-wwq2 SixLabors.ImageSharp (NuGet) Fixed in 4.1.1 Advisory →

Timeline

  1. 2026-10-06 Threatist record created from CVE-2026-106118
  2. 2026-10-07 Alias added: GHSA-v76p-62qx-wwq2
  3. 2026-10-07 Fix available: NuGet/[email protected] · GHSA-v76p-62qx-wwq2
  4. 2026-10-07 CVSS score added · GHSA-v76p-62qx-wwq2
  5. 2026-10-07 Weakness changed · GHSA-v76p-62qx-wwq2
  6. 2026-10-07 6 new references · GHSA-v76p-62qx-wwq2
  7. 2026-10-07 Priority changed: LOW → MEDIUM

References

Advisory 1

Other 8

  • 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
See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences