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NVD / CVE Program· CNA redhat

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

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: bpftool (AlmaLinux:8) 4.18.0-513.11.1.el8_9; kernel (AlmaLinux:8) 4.18.0-513.11.1.el8_9; kernel-abi-stablelists (AlmaLinux:8) 4.18.0-513.11.1.el8_9.

Low priority for now. Upgrade to bpftool (AlmaLinux:8) 4.18.0-513.11.1.el8_9; kernel (AlmaLinux:8) 4.18.0-513.11.1.el8_9; kernel-abi-stablelists (AlmaLinux:8) 4.18.0-513.11.1.el8_9 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Oct 23, 2023
Updated
Jun 17, 2026
EPSS
0.2% · 20th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · redhat
7.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-5633

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
redhatcodeready linux builder
redhatcodeready linux builder eus
redhatcodeready linux builder for arm64
redhatcodeready linux builder for arm64 eus
redhatcodeready linux builder for ibm z systems
redhatcodeready linux builder for ibm z systems eus
redhatcodeready linux builder for power little endian
redhatcodeready linux builder for power little endian eus
redhatenterprise linux
redhatenterprise linux eus
redhatenterprise linux for arm 64

and 10 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.1.13 and later · before 6.1.75
  • linux linux kernel6.2 and later · before 6.5.8
  • linux linux kernel6.6
  • redhat codeready linux builder8.0
  • redhat codeready linux builder9.0
  • redhat codeready linux builder eus8.8
  • redhat codeready linux builder eus9.2
  • redhat codeready linux builder eus9.4
  • redhat codeready linux builder for arm648.0_aarch64
  • redhat codeready linux builder for arm649.0_aarch64
  • redhat codeready linux builder for arm64 eus8.8_aarch64
  • redhat codeready linux builder for arm64 eus9.2_aarch64
  • redhat codeready linux builder for arm64 eus9.4_aarch64
  • redhat codeready linux builder for ibm z systems9.0_s390x
  • redhat codeready linux builder for ibm z systems eus9.2_s390x
  • redhat codeready linux builder for ibm z systems eus9.4_s390x
  • redhat codeready linux builder for power little endian8.0_ppc64le
  • redhat codeready linux builder for power little endian9.0_ppc64le
  • redhat codeready linux builder for power little endian eus8.8_ppc64le
  • redhat codeready linux builder for power little endian eus9.2_ppc64le

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsunknown
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8

    • 0:4.18.0-513.11.1.rt7.313.el8_9 and laternot affected · rpm
    • 0:4.18.0-513.11.1.el8_9 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support

    • 0:4.18.0-477.51.1.el8_8 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 9

    • 0:5.14.0-362.18.1.el9_3 and laternot affected · rpm
    • 0:5.14.0-362.18.1.el9_3 and laternot affected · rpm
    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support

    • 0:5.14.0-284.75.1.el9_2 and laternot affected · rpm
    • 0:5.14.0-284.75.1.rt14.360.el9_2 and laternot affected · rpm

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernelbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-corebefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-cross-headersbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-debugbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-debug-corebefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-debug-develbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-develbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-docbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-modulesbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-modules-extrabefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-toolsbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-tools-libsbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-tools-libs-develbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-zfcpdumpbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-zfcpdump-corebefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-zfcpdump-develbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-zfcpdump-modulesbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8kernel-zfcpdump-modules-extrabefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8perfbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9
AlmaLinux:8python3-perfbefore 4.18.0-513.11.1.el8_94.18.0-513.11.1.el8_9

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-40791Oct 15, 2023 · extract_user_to_sg in lib/scatterlist.c in the Linux kernel before 6.4.12 fails to unpin pages in a certain situation, as demonstrated by a
    25Monitor
  • ← EarlierCVE-2023-45898Oct 16, 2023 · The Linux kernel before 6.5.4 has an es1 use-after-free in fs/ext4/extents_status.c, related to ext4_es_insert_extent.
    31Monitor
  • Later →CVE-2023-43506Oct 25, 2023 · Local Privilege Escalation in ClearPass OnGuard Linux Agent
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:bpftool4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-513.11.1.el8_9 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.76-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch645.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-64kb5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-debug5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-default5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-default-base5.14.21-150500.55.39.1.150500.6.17.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-docs5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-kvmsmall5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-obs-build5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-obs-qa5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-source5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-syms5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-zfcpdump5.14.21-150500.55.39.1 · openSUSE:Leap 15.5Package registry (OSV)
red hat:bpftool0:4.18.0-513.11.1.el8_9 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-513.11.1.el8_9 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-513.11.1.el8_9 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-513.11.1.el8_9 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-513.11.1.el8_9 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+20

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-911 · Improper Update of Reference Count

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records