CVE-2020-36385Public exploit

Kernel code execution via RDMA context race

Published Jun 7, 2021 · Updated Aug 4, 2024

Use-after-free in Linux kernel RDMA UCMA before 5.10 allows local users to crash the system or execute code via concurrent ID migration. ucma_migrate_id() can leave a context reachable through ctx_list while ucma_close() frees it, allowing ucma_close() to read the freed object. Reaching the race requires local interaction with the RDMA userspace connection-manager interface; successful code execution runs in kernel context.

CVSS severity7.8
High
EPSS probability1.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel RDMA UCMA before 5.10 allows local users to crash the system or execute code via concurrent ID migration. ucma_migrate_id() can leave a context reachable through ctx_list while ucma_close() frees it, allowing ucma_close() to read the freed object. Reaching the race requires local interaction with the RDMA userspace connection-manager interface; successful code execution runs in kernel context.

The record

CVE
CVE-2020-36385
Published
Jun 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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