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Vulnerabilities

Vulnerability · CVE-2025-65821

As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as deta

Published Dec 10, 2025 · catalog updated Dec 11, 2025 · As UART download mode

Last checked Oct 27, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-65821. EPSS is 0.37%. Act only if a listed version of As UART download mode is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (As UART download mode).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.37%
Remediation
Vendor / distro source
Affected products
vendor n/a n/a n/a

As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as details about the current and previous Wi-Fi network from the NVS partition. Additionally, this allows the adversary to reflash the device with their own firmware which may contain malicious modifications.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor n/a n/a n/an/a

How to fix CVE-2025-65821

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-65821. EPSS is 0.37%. Act only if a listed version of As UART download mode is installed.

Which versions are affected?

Compare what you have installed with n/a n/a n/a n/a. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.37%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 10, 2025 · EUVD

    Detected

    As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as details about the current and previous Wi-Fi network from the NVS partition. Additionally, this allows the adversary to reflash the device with their own firmware which may contain malicious modifications.

  2. Dec 11, 2025 · EUVD

    Updated

    As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as details about the current and previous Wi-Fi network from the NVS partition. Additionally, this allows the adversary to reflash the device with their own firmware which may contain malicious modifications.

Sources

  • CVE.orgVulnerability recordCVE-2025-65821

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-65821

    30-day exploitation probability 0.37%

    first.org
  • EUVDVulnerability recordEUVD-2025-202625

    As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as details about the current and previous Wi-Fi network from the NVS partition. Additionally, this allows t

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 27, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgOct 27, 2026
  • FIRST EPSSOct 27, 2026
  • EUVDOct 27, 2026