CVE-2021-1940Public exploit

Kernel code execution via asynchronous NPU cleanup

Published Jul 13, 2021 · Updated Aug 3, 2024

Use-after-free in Qualcomm Snapdragon NPU drivers allows local users to execute kernel code through an asynchronous neural-network job. When a busy NPU job remains active as its device file closes, npu_close frees the client after cleanup skips the executing network, leaving network->client dangling for the completion handler. An untrusted application with access to /dev/msm_npu can trigger the race and cross from its app domain into kernel execution, affecting confidentiality, integrity, and availability.

CVSS severity8.4
High
EPSS probability0.18%
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 Qualcomm Snapdragon NPU drivers allows local users to execute kernel code through an asynchronous neural-network job. When a busy NPU job remains active as its device file closes, npu_close frees the client after cleanup skips the executing network, leaving network->client dangling for the completion handler. An untrusted application with access to /dev/msm_npu can trigger the race and cross from its app domain into kernel execution, affecting confidentiality, integrity, and availability.

The record

CVE
CVE-2021-1940
Published
Jul 13, 2021
Updated
Aug 3, 2024
Vendor
Qualcomm
Product
Snapdragon
Classifications
CWE-416, T1404
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=AQT1000, AR8031, AR8035, CSRA6620, CSRA6640, FSM10055, FSM10056, QCA6391, QCA6420, QCA6430, QCA6564, QCA6564A, QCA6564AU, QCA6574, QCA6574A, QCA6574AU, QCA6584AU, QCA6595AU, QCA6696, QCA8337, QCM6125, QCS405, QCS410, QCS610, QCS6125, SA415M, SA515M, SA6145P, SA6155, SA6155P, SA8155, SA8155P, SA8195P, SD 675, SD 8C, SD 8CX, SD660, SD665, SD675, SD678, SD720G, SD730, SD855, SDA429W, SDX50M, SDX55, SDX55M, SM6250, SM6250P, WCD9335, WCD9340, WCD9341, WCD9370, WCD9375, WCD9380, WCN3610, WCN3620, WCN3660B, WCN3950, WCN3980, WCN3988, WCN3990, WCN3991, WCN3998, WCN3999, WSA8810, WSA8815

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Qualcomm · Snapdragonversion=AQT1000, AR8031, AR8035, CSRA6620, CSRA6640, FSM10055, FSM10056, QCA6391, QCA6420, QCA6430, QCA6564, QCA6564A, QCA6564AU, QCA6574, QCA6574A, QCA6574AU, QCA6584AU, QCA6595AU, QCA6696, QCA8337, QCM6125, QCS405, QCS410, QCS610, QCS6125, SA415M, SA515M, SA6145P, SA6155, SA6155P, SA8155, SA8155P, SA8195P, SD 675, SD 8C, SD 8CX, SD660, SD665, SD675, SD678, SD720G, SD730, SD855, SDA429W, SDX50M, SDX55, SDX55M, SM6250, SM6250P, WCD9335, WCD9340, WCD9341, WCD9370, WCD9375, WCD9380, WCN3610, WCN3620, WCN3660B, WCN3950, WCN3980, WCN3988, WCN3990, WCN3991, WCN3998, WCN3999, WSA8810, WSA8815

Published CVSS scores

8.4Qualcomm, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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
T1404Exploitation 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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