CVE-2026-40031: MemProcFS before 5.17 contains multiple unsafe library-loading patterns that enable DLL and shared-library hij

Q: How do I fix CVE-2026-40031?

memprocfs: upgrade to 5.17. Exact commands for each OS are on this page.

Q: Is CVE-2026-40031 being exploited?

CVE-2026-40031 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40031 affect?

CVE-2026-40031 affects memprocfs. Severity is high (CVSS 7.8). MemProcFS before 5.17 contains multiple unsafe library-loading patterns that enable DLL and shared-library hijacking across six attack surfaces, including bare-name LoadLibraryU and dlopen calls without path qualification for vmmpyc, libMSC

Routine

HIGH 7.8UPGRADE

CVE-2026-40031 is a high-severity flaw (CVSS 7.8) affecting memprocfs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

MemProcFS before 5.17 contains multiple unsafe library-loading patterns that enable DLL and shared-library hijacking across six attack surfaces, including bare-name LoadLibraryU and dlopen calls without path qualification for vmmpyc, libMSCompression, and plugin DLLs. An attacker who places a malicious DLL or shared library in the working directory or manipulates LD_LIBRARY_PATH can achieve arbitrary code execution when MemProcFS loads.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.1% (top 96%)
CISA exploited list	No
Weakness	CWE-427
Published	2026-04-08
Last modified	2026-07-24

Publisher (CNA): VulnCheck · Vendor: ufrisk

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-08 22:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

ufrisk memprocfs UPGRADE

Affected: < 5.17

Fixed in: 5.17

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy memprocfs || rpm -q memprocfs || memprocfs --version

2. UPGRADE to 5.17 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade memprocfs

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade memprocfs

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
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-2026-40031?

memprocfs: upgrade to 5.17. Exact commands for each OS are on this page.

Is CVE-2026-40031 being exploited?

CVE-2026-40031 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-2026-40031 affect?

CVE-2026-40031 affects memprocfs. Severity is high (CVSS 7.8). MemProcFS before 5.17 contains multiple unsafe library-loading patterns that enable DLL and shared-library hijacking across six attack surfaces, including bare-name LoadLibraryU and dlopen calls without path qualification for vmmpyc, libMSC

How urgent is CVE-2026-40031?

Priority 28/100. High severity

References

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