OSV Malicious Advisory
scanned 2h ago · by OpenSSF/OSVOpenSSF/OSV advisory MAL-2026-5842 confirms this npm version as malicious. lib/mirror.js line 13 contains a Buffer.from(..., "base64").toString("utf8") pattern. This decoding primitive is common in benign code (parsing JWTs, decoding configuration, handling embedded assets) but is also used to obfuscate hardcoded URLs, payloads, or credentials. Contextual tracing of how the decoded value is used did not complete, so intent cannot be determined from the available evidence...
Advisory
MAL-2026-5842
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in browserslist-db-sync (npm)
Details
lib/mirror.js line 13 contains a Buffer.from(..., "base64").toString("utf8") pattern. This decoding primitive is common in benign code (parsing JWTs, decoding configuration, handling embedded assets) but is also used to obfuscate hardcoded URLs, payloads, or credentials. Contextual tracing of how the decoded value is used did not complete, so intent cannot be determined from the available evidence. The package name suggests a browserslist database mirror/sync utility; a human reviewer should confirm whether the decoded data is benign content (configuration, mirror URL) or hides attacker-controlled strings or executable payload.
## Source: ghsa-malware (1e7eebaf0ec5e5d89501d240e0e11dfd758c9a9c6bcaf74a29a2dcabf1a1f502) Any 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.
Decision reason
OpenSSF Malicious Packages via OSV confirms browserslist-db-sync@1.0.6 as malicious (MAL-2026-5842): Malicious code in browserslist-db-sync (npm)
References
Source & flagged code
0 flaggedNo flagged code excerpts are attached to this scan.
Findings
1 High
HighOsv Malicious Advisory