EUVD-2026-93553
GHSA-ffp7-56pq-64mr
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessUpload image with malformed ICC profile
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DeliveryLUT16 declares >4 output channels
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ExploitInterpolation writes past Vector4 destination
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ExecutionHeap/stack memory corrupted
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ImpactProcess terminates (DoS)
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, write limits
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires the application to have explicitly set DecoderOptions.ColorProfileHandling to Convert; the default Preserve mode does not invoke ICC conversion and is not vulnerable. The attacker must supply an image containing a malformed embedded ICC profile whose LUT16 transform (processed by ClutCalculator.Calculate or LutEntryCalculator.CalculateLut) declares more than four input/output channels or tone-response curves, causing writes beyond the four-float Vector4 destination. Affected versions are 4.0.0 through 4.1.1; the primary limiting factor is the non-default Convert configuration, which significantly reduces the exposed population despite the unauthenticated network vector. |
| Impact | This is a memory-corruption (CWE-787, out-of-bounds write) flaw in SixLabors ImageSharp that the vendor advisory (GHSA-ffp7-56pq-64mr) and the fixing PR #3187 confirm. The NVD CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, 7.5) indicates network-reachable, unauthenticated, low-complexity exploitation with impact limited to availability - consistent with the description, which states the overflow 'can corrupt memory and terminate the process' rather than achieve code execution or data disclosure. No EPSS score, KEV listing, or POC was provided in the input, so exploitation probability cannot be quantified and there is no public exploit identified at time of analysis. The single most important mitigating signal is NOT reflected in the CVSS score: the code path only runs when DecoderOptions.ColorProfileHandling is explicitly set to Convert; the default Preserve mode does not run ICC conversion and is unaffected. This materially narrows real-world exposure to the subset of applications that opt into color conversion, making this a conditional availability/DoS issue rather than a broadly exploitable critical flaw. Treat as medium-priority patch urgency for deployments known to use Convert mode, lower otherwise. |
| Exploit ScenarioDerived | An application using ImageSharp 4.0.0-4.1.1 with DecoderOptions.ColorProfileHandling=Convert accepts user-supplied images (e.g., an upload/thumbnail service). An attacker submits an image with a malformed embedded ICC profile whose LUT16 transform declares more than four output channels, causing ClutCalculator/LutEntryCalculator to write beyond the four-float Vector4 destination, corrupting memory and crashing the worker process. No public exploit code was identified; impact is denial of service, not confirmed code execution. |
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Alert meAnalysisAIv1 – Oct 06, 2026
Memory corruption in SixLabors ImageSharp 4.0.0 through 4.1.1 allows an unauthenticated remote attacker to crash or destabilize a host process by supplying an image whose embedded ICC profile declares more than four LUT16 input/output channels, causing out-of-bounds writes past a four-float internal buffer. The flaw is only reachable when an application has explicitly set DecoderOptions.ColorProfileHandling to Convert, since the default Preserve mode does not run ICC conversion; the independent assessment scores it CVSS 3.1 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), reflecting an availability-only impact rather than data disclosure or modification. No public exploit code was identified at time of analysis, and the issue is fixed in version 4.1.2.
RemediationAI
Vendor-released patch: ImageSharp 4.1.2 - upgrade the SixLabors.ImageSharp package to 4.1.2 or later and rebuild, as documented in GHSA-ffp7-56pq-64mr (https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-ffp7-56pq-64mr), PR https://github.com/SixLabors/ImageSharp/pull/3187, commit b03f0ed7e5be760eecc740fa53dd166b18ae9b23, and release https://github.com/SixLabors/ImageSharp/releases/tag/v4.1.2. If an immediate upgrade is not possible, the most effective compensating control is to stop invoking the vulnerable code path entirely by leaving DecoderOptions.ColorProfileHandling at - or explicitly setting it back to - the default Preserve value, which disables ICC conversion; the trade-off is that embedded profiles are no longer applied, so images may render with inaccurate colors on calibrated or wide-gamut workflows. Additionally, treat image decoding as hostile input: run decoding in a low-privilege, resource-capped worker process or sandbox so any memory corruption or process termination is contained rather than affecting the primary service, and reject or re-encode uploaded images with a defensive sanitizer before they reach ICC-aware processing. Note that no public exploit code was identified at time of analysis, so the priority is determined by whether Convert mode is actually enabled in your deployment; audit for DecoderOptions.ColorProfileHandling usage to establish exposure before scheduling the upgrade.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in nuget, euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
ImageSharp is a cross-platform .NET 2D graphics library, and this issue lives in its ICC color-profile processing pipeline. When a profile is applied, ClutCalculator.Calculate and LutEntryCalculator.CalculateLut interpolate color-lookup-table (CLUT) and tone-response-curve data, but the implementation stores intermediate and final values in System.Numerics.Vector4 - a fixed four-float (16-byte) destination. A LUT16 tag in a malformed embedded profile can legally declare more than four input or output channels, and the code performed no bounds check on that declared count, so it wrote one additional float per extra channel, an out-of-bounds write of class CWE-787 (the vendor's patch also guards TrcCalculator's entry count). The fix, delivered through PR #3187 and the v4.1.2 release, adds explicit InputChannelCount/OutputChannelCount and TRC entry-count checks that throw InvalidIccProfileException instead of writing past the vector, and it introduces BufferedReadStreamExtensions (IsReadRangeValid/TryGetReadLength/Skip) with overflow-safe range validation so untrusted declared lengths cannot wrap or exceed the stream. The vulnerable path is gated behind DecoderOptions.ColorProfileHandling = Convert; the default Preserve mode never executes ICC conversion, which is the primary factor limiting the exposed population despite the network-reachable, unauthenticated trigger.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
A crafted image reliably triggers the overflow against a Convert-configured service with no auth or user interaction (AV:N/AC:L/PR:N/UI:N); impact is process crash only, so C:N/I:N/A:H.
Primary rating from Vendor (GitHub_M).
CVSS VectorVendor: GitHub_M
Lifecycle Timeline
2DescriptionCVE.org
ImageSharp is a 2D graphics library. From 4.0.0 until 4.1.2, ICC LUT16 conversion accepts more than four output channels even though ClutCalculator.Calculate and LutEntryCalculator.CalculateLut store intermediate and output values in Vector4. When DecoderOptions.ColorProfileHandling is set to Convert, a malformed embedded profile can direct interpolation and output-LUT operations to write one float per declared channel beyond the four-float destination. This can corrupt memory and terminate the process; the default Preserve mode does not run ICC conversion. This issue is fixed in version 4.1.2.
Technical POC Analysis
Out-of-bounds write (CWE-787) in the ICC LUT16 conversion path of SixLabors.ImageSharp (NuGet).
Full technical POC analysis - root cause, step-by-step exploitation and patch breakdown - is part of the Pro and Business plans.
Executive ViewAI
SixLabors ImageSharp versions 4.0.0 through 4.1.1 are vulnerable to a memory corruption issue that could allow an unauthenticated remote attacker to crash or destabilize a host process when processing a malicious image, but only if the application has enabled the non-default ICC color conversion mode. This availability-only flaw could disrupt business services for organizations that handle untrusted images with that configuration, and while there is no public exploit identified at time of analysis, the potential for denial-of-service makes it a priority. Leadership should direct remediation efforts to upgrade to version 4.1.2 or disable the vulnerable conversion setting.
Apply vendor patch.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Vulnrichment
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.
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