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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-106111: 0.28% estimated exploitation activity in the next 30 days; percentile 20.60 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A crafted ZIP-compressed OpenEXR image can return stale memory from a prior ImageSharp operation as decoded pixels. The ZIP decoder accepts a non-empty inflate result shorter than the EXR block's required size, then the EXR decoder reads the full expected block. This is a process-local, cross-operation information-disclosure defect. It is relevant when an application uses the shared Configuration.Default allocator for separate image operations and exposes pixels or output derived from a later attacker-controlled EXR decode. Whether that creates a network attack path depends on the host application. No active exploitation is known. Affected package and versions - Package: SixLabors.ImageSharp (NuGet) - Affected published releases: 4.0.0, 4.1.0, and 4.1.1 - Affected range: = 4.0.0, <= 4.1.1 - Commit 0815358f9202a78bc7f3b83e19282dc3654b500f corresponds to release v4.1.1. EXR support first appears in v4.0.0. The cross-operation PoC exposes the prior-operation marker on each…

Published by the source

7 Oct 2026, 20:24 UTC

Last modified by the source

7 Oct 2026, 20:30 UTC

Source last checked

26 Oct 2026, 17:05 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-4q3p-rj5x-xv7p

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-4q3p-rj5x-xv7p

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# Patch Next advisory brief: CVE-2026-106111

Advisory: ImageSharp: EXR ZIP decoder can expose stale allocator data after a short inflate
IDs: CVE-2026-106111, GHSA-4q3p-rj5x-xv7p
Record: https://patchnext.com/advisories/cve-2026-106111 (revision 2, source checked 26 Oct 2026, 17:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sixlabors.imagesharp 4.1.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet sixlabors.imagesharp: affected >= 4.0.0, <= 4.1.1; fixed in 4.1.2

## Suggested inspection (read-only)
- NuGet sixlabors.imagesharp: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sixlabors.imagesharp.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-4q3p-rj5x-xv7p (OSV record GHSA-4q3p-rj5x-xv7p lists affected ranges: NuGet sixlabors.imagesharp >=4.0.0 <4.1.2 (fixed))
- Verified: https://github.com/advisories/GHSA-4q3p-rj5x-xv7p (GitHub-reviewed advisory GHSA-4q3p-rj5x-xv7p lists affected ranges: NuGet sixlabors.imagesharp >=4.0.0 <=4.1.1)

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