{"id":"MAL-2026-18334","revision":null,"records":[{"revision":"8edfb0fb2bad4787b10d2acd5b831c59","observedAt":"2026-10-29T15:12:22.973+00:00","statement":{"source":"osv","id":"MAL-2026-18334","aliases":["GHSA-fh55-fq5h-h352"],"title":"Malicious code in postcss-semantic-themes (npm)","description":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (21c91b39929f03c30e501726fc2d1c1fa43f17bf2ed77bda52380e563c1171e0)\nThe package advertises itself as a zero-runtime CSS theming kit but on require/import executes a chain of obfuscated JavaScript modules. lib.mjs imports tokens.mjs, which top-level imports cache-warm.mjs — a ~279KB single-line file consisting of a hex-named string array of XOR/base64-encoded blobs decoded at runtime. Three additional sibling modules of the same shape (build-cache.mjs ~203KB, cache-sweep.mjs ~295KB, workspaces.js ~290KB) are shipped and listed in the published files manifest. Alongside the JavaScript loader, the tarball bundles prebuilt N-API native binaries at native/{linux,darwin,win32}/{arm64,x64}/cache-probe.node whose exported symbols implement extensive hypervisor, container, and sandbox detection (VMDetect/VMDetector classes, hypervisor_bit, qemu_fw_cfg, systemd_virt, dockerenv, bluestacks, vbox_module, podman_file, wsl_proc_subdir, amd_sev_msr, azure, chassis_vendor, mac_address_check, is_x86_process_on_arm). None of this has any role in CSS custom-property emission. The README instructs installation as `npm install -D tailwindcss@npm:postcss-semantic-themes`, aliasing the legitimate tailwindcss name onto this package so existing `import 'tailwindcss'` call sites resolve to the obfuscated loader. The combination of an import-time obfuscated loader, multiple additional staged obfuscated payloads, environment-fingerprinting native code to gate execution to non-analyst hosts, and a brandjacking install instruction is the structural shape of a staged supply-chain payload rather than a theming plugin.\n\n## Source: ghsa-malware (d188bb5d3c330ed5c438865b3787cca124861eefe2c8e094e58511bbca437e09)\nAny computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.\n","state":0,"publishedAt":"2026-10-26T16:17:58+00:00","modifiedAt":"2026-10-29T14:45:07.2572353+00:00","affected":[{"ecosystem":"npm","name":"postcss-semantic-themes","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"}]}],"versions":["1.0.0","1.0.1","0.0.0-stage"],"rawVersionEvidence":null}],"metrics":[],"references":["https://github.com/advisories/GHSA-fh55-fq5h-h352","https://www.npmjs.com/package/postcss-semantic-themes/v/1.0.0","https://www.npmjs.com/package/postcss-semantic-themes/v/1.0.1","https://www.npmjs.com/package/postcss-semantic-themes/v/0.0.0-stage"],"sourceUrl":"https://osv.dev/vulnerability/MAL-2026-18334","license":"OSV · upstream source license applies","key":"osv:MAL-2026-18334","identifiers":["MAL-2026-18334","GHSA-fh55-fq5h-h352"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-07T06:27:05.6380447+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-07T06:27:05.6380447+00:00","lastSuccessAt":"2026-11-07T06:27:05.7932457+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:05.7932469+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-bb5c9d5a08063ef076042e33dd72a7d0ffa4c4487efdcf3106e29ba55ec2ad57-6f544c2f3953f500ddb5b39526af1c06f4dafd806ddc7bf6476fb6444529ee07","complete":true,"records":420723,"lastAttemptAt":"2026-11-07T06:27:04.4118644+00:00","lastSuccessAt":"2026-11-07T06:27:04.3307229+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:04.4118644+00:00","snapshotPublishedAt":"2026-11-07T05:27:23+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-f3bff9471edc48448e31845a67a4407b","complete":true,"records":13630,"lastAttemptAt":"2026-11-07T06:38:40.0754161+00:00","lastSuccessAt":"2026-11-07T06:38:40.073+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:38:40.073+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13685,"expectedIdentifiers":13685,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-07T06:27:05.6380447+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-07T06:27:05.6380447+00:00","lastSuccessAt":"2026-11-07T06:27:05.7940505+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:05.7940508+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-1262a9fa83024e28a1560dfc0c9cdf3c","complete":true,"records":13645,"lastAttemptAt":"2026-11-07T06:27:08.5367847+00:00","lastSuccessAt":"2026-11-07T06:27:08.533+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:08.533+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13685,"expectedIdentifiers":13685,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-0eb4d6dde62dffacd040ad992d4fd5a65cd7d0dc5f5f4cfa8b41967fc6f9ca5f","complete":true,"records":9914,"lastAttemptAt":"2026-11-07T06:27:05.1996809+00:00","lastSuccessAt":"2026-11-06T20:10:36.6450506+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:05.1996809+00:00","snapshotPublishedAt":"2026-11-06T20:02:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-07T06:27:04.6304807+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:04.6304807+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-335633e78a15c9cde10a6025895b5617717087fb945489ae7e15d377bacf34a9","complete":true,"records":3055,"lastAttemptAt":"2026-11-07T06:27:05.5809672+00:00","lastSuccessAt":"2026-11-06T16:03:00.7615789+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:05.5809672+00:00","snapshotPublishedAt":"2026-11-06T16:02:48+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-a0b728bc1c5526b5429930c00621636eba8655069c176697c3080f8377619ad7","complete":true,"records":231291,"lastAttemptAt":"2026-11-07T06:27:05.0945652+00:00","lastSuccessAt":"2026-11-07T00:28:51.1983528+00:00","error":null,"lastVerifiedAt":"2026-11-07T06:27:05.0945652+00:00","snapshotPublishedAt":"2026-11-06T23:33:08+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}