How to reproduce:

Create a new project
Create a URP Unlit or SRP Blit Shader and open it
Anywhere in the “SubShader” part paste “ColorMask RGB -1” and save
Observe the crash

Reproducible with: 6000.6.0a7, 6000.6.4f1, 6000.7.0b3, 7000.0.0a5
Not reproducible with: 6000.0.84f1, 6000.3.25f1 , 6000.6.0a6

Reproducible on: Windows 10 (User), Windows 11
Not reproducible with: No other environments tested

Note: Reproducible with DirectX11, DirectX12, Vulkan; OpenGL not tested

First few lines of the stack trace:
0x00007FFC8E98CA0A (Unity) ShaderLab::DataTransferVisitor::Visit
0x00007FFC8E9470DC (Unity) ShaderApiReflection::DataStructures::VisitorPattern::detail::Walk<ShaderLab::SyntaxTreeVisitor & __ptr64,ShaderLab::SyntaxNodes::ColorMaskNode>
0x00007FFC8E9457B9 (Unity) ShaderApiReflection::DataStructures::VisitorPattern::detail::TryWalk<ShaderLab::SyntaxTreeVisitor & __ptr64,ShaderLab::SyntaxNodes::LodNode,ShaderLab::SyntaxNodes::NameNode,ShaderLab::SyntaxNodes::ListNode<ShaderLab::SyntaxNodes::TagNode>,ShaderLab::SyntaxNodes::ListNode<ShaderLab::SyntaxNodes::BindChannelNode>,ShaderLab::SyntaxNodes::MaterialBlockNode,ShaderLab::SyntaxNodes::FogBlockNode,ShaderLab::SyntaxNodes::ColorNode,ShaderLab::SyntaxNodes::LightingNode,ShaderLab::SyntaxNodes::AlphaToMaskNode,ShaderLab::SyntaxNodes::ZTestNode,ShaderLab::SyntaxNodes::ZWriteNode,ShaderLab::SyntaxNodes::ZClipNode,ShaderLab::SyntaxNodes::ConservativeNode,ShaderLab::SyntaxNodes::ColorMaterialNode,ShaderLab::SyntaxNodes::AlphaTestNode,ShaderLab::SyntaxNodes::CullNode,ShaderLab::SyntaxNodes::ColorMaskNode,ShaderLab::SyntaxNodes::BlendNode,ShaderLab::SyntaxNodes::BlendOpNode,ShaderLab::SyntaxNodes::StencilNode,ShaderLab::SyntaxNodes::SeparateSpecularNode,ShaderLab::SyntaxNodes::OffsetNode,ShaderLab::S0x00007FFC8E945ED6 (Unity) ShaderApiReflection::DataStructures::VisitorPattern::detail::TryWalk<ShaderLab::SyntaxTreeVisitor & __ptr64,ShaderLab::SyntaxNodes::SubShaderNode,ShaderLab::SyntaxNodes::CategoryNode,ShaderLab::SyntaxNodes::FallbackNode,ShaderLab::SyntaxNodes::DependencyNode,ShaderLab::SyntaxNodes::CustomEditorNode>
0x00007FFC8E94EDB9 (Unity) ShaderLab::SyntaxTreeVisitor::Walk