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NVD / CVE Program· CNA Linux

CVE-2024-36909: Drivers: hv: vmbus: Don't free ring buffers that couldn't be re-encrypted

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.24% (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: Linux Linux 2f622008bf784a9f5dd17baa19223cc2ac30a039, 30d18df6567be09c1433e81993e35e3da573ac48, 82f9e213b124a7d2bb5b16ea35d570260ef467e0; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.
  • Severity is disputed: the assigning authority (CNA) scores it 9.3, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 2f622008bf784a9f5dd17baa19223cc2ac30a039, 30d18df6567be09c1433e81993e35e3da573ac48, 82f9e213b124a7d2bb5b16ea35d570260ef467e0; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes 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

In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: vmbus: Don't free ring buffers that couldn't be re-encrypted In CoCo VMs it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. The VMBus ring buffer code could free decrypted/shared pages if set_memory_decrypted() fails. Check the decrypted field in the struct vmbus_gpadl for the ring buffers to decide whether to free the memory.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 30, 2024
Updated
Aug 5, 2026
EPSS
0.2% · 15th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
9.3
3.8 point gap

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

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-2024-36909

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

Affected versions

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

  • linux linux kernelbefore 6.1.91
  • linux linux kernel6.2 and later · before 6.6.31
  • linux linux kernel6.7 and later · before 6.8.10
  • linux linux kernel6.9

Versions reported by the vendor

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

  • Linux Linux

    • 5.16affected
    • d4dccf353db80e209f262e3973c834e6e48ba9a9 and later · before 2f622008bf784a9f5dd17baa19223cc2ac30a039affected · git
    • d4dccf353db80e209f262e3973c834e6e48ba9a9 and later · before 82f9e213b124a7d2bb5b16ea35d570260ef467e0affected · git
    • d4dccf353db80e209f262e3973c834e6e48ba9a9 and later · before a9212a4e2963a7fbe3864ba33dc551d4ad8d0abbaffected · git
    • d4dccf353db80e209f262e3973c834e6e48ba9a9 and later · before 30d18df6567be09c1433e81993e35e3da573ac48affected · git
    • before 5.16not affected · semver
    • 6.1.91 and later · up to and including 6.1.*not affected · semver
    • 6.6.31 and later · up to and including 6.6.*not affected · semver
    • 6.8.10 and later · up to and including 6.8.*not affected · semver
    • 6.9 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.94-16.1.94-1
Debian:13linuxbefore 6.8.11-16.8.11-1

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-2024-36906May 30, 2024 · ARM: 9381/1: kasan: clear stale stack poison
    31Monitor
  • ← EarlierCVE-2024-36908May 30, 2024 · blk-iocost: do not WARN if iocg was already offlined
    22Monitor
  • Later →CVE-2024-36910May 30, 2024 · uio_hv_generic: Don't free decrypted memory
    33Monitor

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
Linux Linux2f622008bf784a9f5dd17baa19223cc2ac30a039Vendor (CNA)
Linux Linux30d18df6567be09c1433e81993e35e3da573ac48Vendor (CNA)
Linux Linux82f9e213b124a7d2bb5b16ea35d570260ef467e0Vendor (CNA)
Linux Linuxa9212a4e2963a7fbe3864ba33dc551d4ad8d0abbVendor (CNA)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.1.94-1 · Debian:12Package registry (OSV)

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.

No history yet (it accumulates with the daily EPSS job).

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.

No credits in the CNA record.

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

Weakness class (CWE)

CWE-401 · Missing Release of Memory after Effective Lifetime

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 (3 more)

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

All records