Information disclosure in kernel
Priority LOW 25CWE-200Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Partial Red Hat: 4 fixed, 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-200.
Summary
A flaw was found in the Linux kernel's OverlayFS subsystem in the way the user mounts the TmpFS filesystem with OverlayFS. This flaw allows a local user to gain access to hidden files that should not be accessible.
Why it matters now
EPSS 0.00353 29th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 fixed, 2 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | kernel | Affects kernel before v5.13.11, Fixed in v5.14-rc6 and later. | — | No fix listed | CNA |
- kernel Vendor— Affected Affects kernel before v5.13.11, Fixed in v5.14-rc6 and later. Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.14 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:* | 5.14 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:* | 5.14 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:* | 5.14 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:* | 5.14 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:* | 5.14 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:* | 5.14 rc5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.14 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:* Versions 5.14 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:* Versions 5.14 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:* Versions 5.14 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:* Versions 5.14 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:* Versions 5.14 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:* Versions 5.14 rc5 Vulnerable ·Linux
Remediation
Red Hat 2 advisories
- RHSA-2021:4356 Released 2021-11-09 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-348.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-348.el8, kernel-4.18.0-348.el8, kernel-abi-stablelists-4.18.0-348.el8 +19
- RHSA-2021:4140 Released 2021-11-09 · Red Hat rating Moderatekernel-rt security and bug fix update
- Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-348.rt7.130.el8, kernel-rt-core-4.18.0-348.rt7.130.el8, kernel-rt-debug-4.18.0-348.rt7.130.el8 +7
- Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-348.rt7.130.el8, kernel-rt-core-4.18.0-348.rt7.130.el8, kernel-rt-debug-4.18.0-348.rt7.130.el8 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2021:4356 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2021:4356 |
| Red Hat Enterprise Linux Real Time (v. 8) | Fixed | RHSA-2021:4140 |
| Red Hat Enterprise Linux Real Time for NFV (v. 8) | Fixed | RHSA-2021:4140 |
Not affected: 2 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3732
- 2026-10-03 Alias added: GHSA-wc3f-5p43-3cxx
References
Patch 3
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2021-3732 · CVE Program
- CVE-2021-3732 · NVD
- FIRST EPSS
- GHSA-wc3f-5p43-3cxx · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3732 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences