CVE-2023-5633: Kernel: vmwgfx: reference count issue leads to use-after-free in surface handling
Vulnerability summary
CVE-2023-5633 is a high (CVSS 7.8) Improper Update of Reference Count vulnerability in linux linux_kernel. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 20.3% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 16 · Related 10Timeline
- 23-10-2023PublishedVulnerability first disclosed.
- 25-02-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.28%
Chance of exploitation in the next 30 days
Percentile
20%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.28% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-911Improper Update of Reference CountThe product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count.
- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu70 products
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
- linux-aws-5.13All versions (No fix recorded)
- linux-aws-5.19All versions (No fix recorded)
Redhat21 products
- codeready_linux_builder8.0 | 9.0
- codeready_linux_builder_eus8.8 | 9.2 | 9.4
- codeready_linux_builder_for_arm648.0_aarch64 | 9.0_aarch64
- codeready_linux_builder_for_arm64_eus8.8_aarch64 | 9.2_aarch64 | 9.4_aarch64
- codeready_linux_builder_for_ibm_z_systems9.0_s390x
Debian1 product
- linux< 6.1.76-1 | < 6.5.8-1
Linux1 product
- linux_kernel≥ 6.1.13, < 6.1.75 | ≥ 6.2, < 6.5.8 | 6.6:rc1 | 6.6:rc2 | 6.6:rc3 | 6.6:rc4 | 6.6:rc5 | 6.6:rc6
4 vendors · 93 products
