pnpm versions older than 10.34.2 for the 10.x series and older than 11.5.3 for the 11.x series contain a flaw in the peer‑suffix normalizer that strips parenthesized text from git, URL, tarball, file, and other opaque locators. Consequently, a crafted source string can normalize to the same value as an already approved source, allowing an attacker to substitute a malicious source that satisfies the approval check and runs during a pnpm install, thereby executing arbitrary code on the host. The issue involves a trust boundary bypass and improper input validation, which map to multiple CWE identifiers (CWE-140, CWE-346, CWE-693, CWE-829).

All installations of pnpm that are earlier than the patched releases, including developers’ local environments and continuous‑integration pipelines that resolve dependencies with these versions, are affected. Any party that can influence a package.json or lockfile that pnpm processes risks inadvertently installing a malicious source.

The CVSS score of 7.5 indicates a moderate‑to‑high severity. The EPSS score of <1% suggests that exploitation is unlikely at this time, and the vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker who can modify a dependency specification—by altering a package.json file, a lockfile, or publishing a new package that pnpm will resolve—can make a crafted source bypass approval checks. This vulnerability, identified by several CWE identifiers including CWE-140, CWE-346, CWE-693, and CWE-829, may allow remote delivery of malicious code if the attacker controls the publishing of a package that vulnerable pnpm installations will resolve.