Payload class · api

Content Type Confusion Canaries

Paired inert request bodies for checking whether gateways, validators, frameworks, and handlers disagree about JSON, form, text, and multipart parsing. Use only a reversible operation on controlled records.

content-typeapiparsergatewayvalidation

Stable IDpayload:content-type-confusion-canariesSource record date2026-08-20Human reviewNot recordedProvenanceSource-linked

Context first

Use as a detection primitive

Paired inert request bodies for checking whether gateways, validators, frameworks, and handlers disagree about JSON, form, text, and multipart parsing. Use only a reversible operation on controlled records.

Do not copy blind

Identify the parser, sink, encoding, and expected non-vulnerable behavior before choosing a sample. Prefer non-destructive markers.

Samples

Recorded payloads

Detection sampleAuthorization required

Confirm the sink and encoding context before use.

Content-Type: application/json | {"marker":"alpha"}

Expected signal: Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
Negative control: Define a known-safe or nonexistent target that should produce a meaningfully different result.
Effect and bounds: Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.

Detection sampleAuthorization required

Confirm the sink and encoding context before use.

Content-Type: application/x-www-form-urlencoded | marker=alpha

Expected signal: Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
Negative control: Define a known-safe or nonexistent target that should produce a meaningfully different result.
Effect and bounds: Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.

Detection sampleAuthorization required

Confirm the sink and encoding context before use.

Content-Type: text/plain | {"marker":"alpha"}

Expected signal: Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
Negative control: Define a known-safe or nonexistent target that should produce a meaningfully different result.
Effect and bounds: Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.

Detection sampleAuthorization required

Confirm the sink and encoding context before use.

Content-Type: application/json; charset=utf-8 | {"marker":"alpha"}

Expected signal: Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
Negative control: Define a known-safe or nonexistent target that should produce a meaningfully different result.
Effect and bounds: Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.

Detection sampleAuthorization required

Confirm the sink and encoding context before use.

Content-Type: application/json | {"marker":"alpha","marker":"beta"}

Expected signal: Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
Negative control: Define a known-safe or nonexistent target that should produce a meaningfully different result.
Effect and bounds: Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.

Source

Attribution

Open the primary collection ↗

Version history: normalized permanent page created 2026-08-20.