CVE-2021-23438

mpath: type confusion can lead to a bypass of CVE-2018-16490

Published 1 Sep 2021Modified 17 Jun 2026CWE 843

In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.

Severity by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

GHSA5.6CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Red Hat5.6CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by GHSA (medium), Red Hat (medium).

Description

This affects the package mpath before 0.8.4. A type confusion vulnerability can lead to a bypass of CVE-2018-16490. In particular, the condition ignoreProperties.indexOf(parts[i]) !== -1 returns -1 if parts[i] is ['__proto__']. This is because the method that has been called if the input is an array is Array.prototype.indexOf() and not String.prototype.indexOf(). They behave differently depending on the type of the input.

Affected packages and fixed versions

Source	Package	Fixed in
npm::GitHub Security Advisory npm	mpath	0.8.4

References

All 9 references

https://www.cve.org/CVERecord?id=CVE-2021-23438

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FindsEvery admitted image is rescanned every 24 hours by default (scan.rescanInterval). When Trivy rates this vulnerability critical for the image's package source, it appears in the image's findings by name. Findings without a fix are left out unless includeUnfixed is on.
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RefusesWith a policy that blocks critical findings, a pod with this image is refused at admission, a rollback to it included. Pods already running are not evicted.
RecordsEach decision is recorded with the policy that ran and its hash, then sealed under a signed checkpoint.

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