CVE-2025-31703

Physical privilege escalation via serial authentication bypass

Published Mar 18, 2026 · Updated Mar 18, 2026

Authentication bypass in Dahua NVR2-4KS3 and XVR recorders built before March 3, 2026 allows physically proximate attackers to escalate privileges. The serial-port interface grants access to a restricted shell, whose authentication mechanism can then be bypassed; Dahua has not disclosed the underlying implementation error. Physical access to the recorder is required, and successful exploitation exposes shell access with increased privileges but no reported service interruption.

CVSS severity2.4
Low
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Dahua NVR2-4KS3 and XVR recorders built before March 3, 2026 allows physically proximate attackers to escalate privileges. The serial-port interface grants access to a restricted shell, whose authentication mechanism can then be bypassed; Dahua has not disclosed the underlying implementation error. Physical access to the recorder is required, and successful exploitation exposes shell access with increased privileges but no reported service interruption.

The record

CVE
CVE-2025-31703
Published
Mar 18, 2026
Updated
Mar 18, 2026
Vendor
Zhejiang Dahua Technology Co., Ltd.
Product
XVR4232AN-I/T
Classifications
CWE-305, T1068
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 18, 2026Record 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=Versions which Build time prior to 3rd March 2026

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Zhejiang Dahua Technology Co., Ltd. · XVR4232AN-I/Tversion=Versions which Build time prior to 3rd March 2026
Zhejiang Dahua Technology Co., Ltd. · NVR2-4KS3 Seriesversion=Versions which Build time prior to 3rd March 2026
Zhejiang Dahua Technology Co., Ltd. · XVR1B16H-I/Tversion=Versions which Build time prior to 3rd March 2026

Published CVSS scores

2.4Dahua TechnologiesCVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-305Authentication Bypass by Primary Weakness
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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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