Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2025-27840

26
FAUCET Score

CVE-2025-27840 describes a medium-severity vulnerability affecting Espressif ESP32 chips and firmware, where 29 hidden HCI commands, including a memory write function (0xFC02), are present. This physical access vulnerability (AV:P) requires high privileges (PR:H) but has high confidentiality and integrity impacts (C:H/I:H). While not currently in CISA KEV or having public exploit code, it has garnered significant community discussion and media coverage, indicating awareness of its potential.

Impacted Technologies

VendorProductVersion(s)CPE
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:espressif:esp32_firmware:-:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.8MEDIUM

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

Attack Vector
PHYSICAL
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
LOW
Exploitability Score
0.3
Impact Score
6.0
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.26%
Probability of exploitation in next 30 days
EPSS Percentile
66.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0126 is in the 98th percentile among its peer group of 48 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.0 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

cheriot.org / auditing/backdoor/2025/03/09/no-esp32-style-backdoor.html
Technical DescriptionThird Party Advisory
darkmentor.com / blog/esp32_non-backdoor
ExploitTechnical DescriptionThird Party Advisory
flyingpenguin.com
Technical DescriptionThird Party Advisory
github.com / em0gi/CVE-2025-27840
Product
github.com / esphome/esphome/discussions/8382
Issue Tracking
github.com / orgs/espruino/discussions/7699
Issue Tracking
github.com / TarlogicSecurity/Talks/blob/main/2025_RootedCon_BluetoothTools.pdf
Third Party Advisory
news.ycombinator.com / item
Issue Tracking
news.ycombinator.com / item
Issue Tracking
reg.rootedcon.com / cfp/schedule/talk/5
Third Party Advisory
bleepingcomputer.com / news/security/undocumented-backdoor-found-in-bluetooth-chip-used-by-a-billion-devices
ExploitPress/Media Coverage
bleepingcomputer.com / news/security/undocumented-commands-found-in-bluetooth-chip-used-by-a-billion-devices
ExploitPress/Media Coverage
espressif.com / en/news/Response_ESP32_Bluetooth
Press/Media Coverage
tarlogic.com / news/backdoor-esp32-chip-infect-ot-devices
Third Party Advisory
x.com / pascal_gujer/status/1898442439704158276
Third Party Advisory