@tybys/wasm-util — Greenflagged

WASI polyfill for browser and some wasm util

Supply chain provenance

Status for the latest visible version.

No SLSA provenance npm registry signatures gitHead linked

Without SLSA provenance there is no cryptographic link between this tarball and the public source — the axios compromise (March 2026) relied on exactly this gap.

Maintainers

toyobayashi

Keywords

wasmwebassemblywasipolyfill

Accepted risks

Findings the reviewer chose to accept rather than block on.

Source	Rule	Reason	Accepted by	When
source-diff	obfuscated-file:lib/cjs/memfs.js	AI (source-diff): This is a bundled/minified copy of the memfs library, consistent with the package's WASI polyfill purpose and its memfs-browser devDependency. Not malicious obfuscation.	ai	2026/04/24
source-diff	obfuscated-file:lib/mjs/memfs.mjs	AI (source-diff): ESM variant of the same bundled memfs library. Same rationale as the CJS version — legitimate minified bundle output.	ai	2026/04/24
source-diff	net-exec-file:lib/cjs/memfs.js	AI (source-diff): False positive: network and eval patterns come from Node.js polyfills within the bundled memfs library, not from dropper/loader logic. Consistent with browser-targeted WASI polyfill.	ai	2026/04/24
source-diff	net-exec-file:lib/mjs/memfs.mjs	AI (source-diff): Same false positive rationale as the CJS variant — bundled Node.js polyfill patterns, not malware.	ai	2026/04/24

Versions (showing 18 of 18)

Version	Deps	Published
0.10.2	1 / 15	2026-05-04
0.10.1	1 / 15	2025-09-11
0.10.0	1 / 15	2025-07-08
0.9.0	1 / 15	2024-05-07
0.8.3	1 / 15	2024-04-21
0.8.2	1 / 15	2024-04-19
0.8.1	1 / 15	2024-01-07
0.8.0	1 / 15	2023-02-26
0.7.0	1 / 15	2023-02-19
0.6.0	1 / 15	2023-02-19
0.5.3	1 / 14	2022-12-11
0.5.2	0 / 14	2022-12-11
0.5.1	0 / 14	2022-12-11
0.5.0	0 / 14	2022-12-11
0.4.0	0 / 14	2022-11-14
0.3.0	1 / 14	2022-11-13
0.2.0	1 / 14	2022-11-01
0.1.0	1 / 14	2022-10-28

v0.10.2

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.10.1

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.10.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.9.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.8.3

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.8.2

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.8.1

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.8.0

5 findings

HIGH New obfuscated file: lib/cjs/memfs.js source-diff

Newly added source file contains lines over 3000 chars, suggesting minified or obfuscated code. New obfuscated files are a strong attack indicator.

HIGH New file with network + code execution: lib/cjs/memfs.js source-diff

Newly added file contains both network calls and dynamic code execution. This is a hallmark of dropper/loader malware.

HIGH New obfuscated file: lib/mjs/memfs.mjs source-diff

Newly added source file contains lines over 3000 chars, suggesting minified or obfuscated code. New obfuscated files are a strong attack indicator.

HIGH New file with network + code execution: lib/mjs/memfs.mjs source-diff

Newly added file contains both network calls and dynamic code execution. This is a hallmark of dropper/loader malware.

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.7.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.6.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.5.3

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.5.2

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.5.1

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.5.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.4.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.3.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.2.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Consider requesting the maintainer enable provenance via CI/CD.

v0.1.0

1 finding

LOW No provenance attestation provenance

Package was published without Sigstore provenance. Only ~12% of npm packages have provenance, so this is common but not ideal.