PatchTheCVECVE-2021-23438: This affects the package mpath before 0.8.4
CVE-2021-23438 is a medium-severity flaw (CVSS 5.6) affecting mpath. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.6 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.7% (top 23%) |
| CISA exploited list | No |
| Weakness | CWE-843 |
| Published | 2021-09-01 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-23438?
mpath: upgrade to 0.8.4. Exact commands for each OS are on this page.
Is CVE-2021-23438 being exploited?
CVE-2021-23438 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-23438 affect?
CVE-2021-23438 affects mpath. Severity is medium (CVSS 5.6). 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 beca
How urgent is CVE-2021-23438?
Priority 49/100. Public exploit reference; Remotely exploitable, no login, no user action