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CVE-2021-4002
A memory leak flaw in the Linux kernel's hugetlbfs memory usage was found in the way the user maps some regions of memory twice using…
- 4.4MediumCVSS base score
- 0.52%Exploitation in 30 daysEPSS · top 56% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A memory leak flaw in the Linux kernel's hugetlbfs memory usage was found in the way the user maps some regions of memory twice using shmget() which are aligned to PUD alignment with the fault of some of the memory pages. A local user could use this flaw to get unauthorized access to some data.
Timeline
ID reserved
By redhat
- 3 months later
· 3 months later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.52% · top 56% of all CVEs (12 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.4.
Affected products
kernel
- affected affects kernel v3.6 and later through v5.15.5.
References
References8
- https://bugzilla.redhat.com/show_bug.cgi?id=2025726 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.openwall.com/lists/oss-security/2021/11/25/1 (opens in a new tab)x_refsource_MISCx_transferred
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=13e4ad2ce8df6e058ef482a31fdd81c725b0f7ea (opens in a new tab)x_refsource_MISCx_transferred
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a4a118f2eead1d6c49e00765de89878288d4b890 (opens in a new tab)x_refsource_MISCx_transferred
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2940-1] linux security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- DSA-5096 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- https://www.oracle.com/security-alerts/cpujul2022.html (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-33909 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-4002)Record last updated .