CVE-2026-106111

ImageSharp: EXR ZIP decoder can expose stale allocator data after a short inflate

Published Oct 6, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed

Description

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.

Analysis

Technical impact

The flaw lies in the EXR ZIP decoder of ImageSharp. When the UndoZipCompression routine processes a ZIP or ZIPS inflate result that is smaller than the EXR block requires, it assembles only a prefix while the decoder still reads the full expected block from a buffer supplied through Configuration.Default. This mismatch allows bytes retained from a previous ImageSharp operation to appear in the decoded pixels, exposing stale allocator data and creating a channel for information disclosure.

Affected Systems

SixLabors ImageSharp versions 4.0.0 through 4.1.2 inclusive are affected. Version 4.1.2 and later contain a patch that eliminates the bug. Earlier releases are not listed as fixed, so they are presumed vulnerable until the security fix is applied.

Risk and Exploitability

The CVSS score of 5.9 indicates medium severity. EPSS data is not available and the flaw is not listed in CISA KEV, suggesting limited known exploitation. An attacker who can deliver a crafted EXR file to an application that uses ImageSharp can trigger the bug, causing the application to leak process‑local image data. The risk is confined to environments where ImageSharp processes external or untrusted EXR images.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

SixLabors

ImageSharp

affected

Version	Status	Constraints
`>= 4.0.0, < 4.1.2`	affected	—

Configuration 1 [-]

cpe:2.3:a:sixlabors:imagesharp:*:*:*:*:*:*:*:*

No data.

Vendor Product Versions

Sixlabors

Imagesharp

Version	Status	Scheme	Platform
`[4.0.0,4.1.2)`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade to ImageSharp 4.1.2 or later to apply the security fix.
If an upgrade is not possible immediately, restrict EXR decoding to trusted inputs and validate that the inflate output size matches the expected EXR block length.
Ensure that any exported or displayed pixel data is sanitized and that raw pixel buffers containing stale data are not exposed to users.

Generated by OpenCVE AI on October 6, 2026 at 19:50 UTC.

Tracking

Advisories

Source	ID	Title
Github GHSA	GHSA-4q3p-rj5x-xv7p	ImageSharp: EXR ZIP decoder can expose stale allocator data after a short inflate

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.280% probability within 30 days)

Exploitation poc

Automatable no

Technical Impact partial

References

Link	Providers
https://github.com/SixLabors/ImageSharp/commit/3c43cf583fdd98eff0f451397affaa31c6a2e6b1
https://github.com/SixLabors/ImageSharp/commit/6ed2a275217d39301e76df42acec2a9533b39d2b
https://github.com/SixLabors/ImageSharp/pull/3187
https://github.com/SixLabors/ImageSharp/releases/tag/v4.1.2
https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-4q3p-rj5x-xv7p

History

Oct 24, 2026 2:00 AM Affected versions updated View changes

Type	Values Removed	Values Added
CPEs		cpe:2.3:a:sixlabors:imagesharp::::::::

Oct 7, 2026 6:15 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Sixlabors Sixlabors imagesharp
Vendors & Products		Sixlabors Sixlabors imagesharp

Oct 6, 2026 7:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Oct 6, 2026 5:45 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		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.
Title		ImageSharp: EXR ZIP decoder can expose stale allocator data after a short inflate
Weaknesses		CWE-226
References		https://github.com/SixLabors/ImageSharp/commit/3c43cf583fdd98eff0f451397affaa31c6a2e6b1 https://github.com/SixLabors/ImageSharp/commit/6ed2a275217d39301e76df42acec2a9533b39d2b https://github.com/SixLabors/ImageSharp/pull/3187 https://github.com/SixLabors/ImageSharp/releases/tag/v4.1.2 https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-4q3p-rj5x-xv7p
Metrics		cvssV3_1 `{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}`