# CVE-2023-4732: Kernel: race between task migrating pages and another task calling exit_mmap to release those same pages getting invalid opcode bug in include/linux/swapops.h

Status: published. Published: 2023-10-03. Updated: 2026-11-07.

A flaw was found in pfn_swap_entry_to_page in memory management subsystem in the Linux Kernel. In this flaw, an attacker with a local user privilege may cause a denial of service problem due to a BUG statement referencing pmd_t x.

## Remediation

- workaround: A possible workaround is disabling Transparent Hugepage (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 8 (kernel-rt): ≥ 0:4.18.0-513.5.1.rt7.307.el8_9; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (kernel): ≥ 0:4.18.0-513.5.1.el8_9; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.6 Extended Update Support (kernel): ≥ 0:4.18.0-372.87.1.el8_6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8.8 Extended Update Support (kernel): ≥ 0:4.18.0-477.36.1.el8_8; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 (kernel): ≥ 0:4.18.0-372.87.1.el8_6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (kernel-rt): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (kernel-rt): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 4.7 (medium); CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.18% as of 2026-11-07; percentile 7.93%

- SSVC: Not available

- Weaknesses: CWE-366

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2023:6901 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2023:7077 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2023:7539 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2024:0412 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2023-4732 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2236982 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2023:6901 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/errata/RHSA-2023:7077 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/errata/RHSA-2023:7539 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/errata/RHSA-2024:0412 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/security/cve/CVE-2023-4732 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred)

- https://bugzilla.redhat.com/show_bug.cgi?id=2236982 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-4732; retrieved 2026-11-07; source updated 2026-11-07

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-4732; retrieved 2026-11-07; source updated Not reported

Revision: e16c67dfddda1788d5791fcade90dca9bbd93ddf83f9332aaf9fe79e1c4ceac3

Canonical: https://y2.dev/cve/CVE-2023-4732

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.