CVE-2026-38427Public exploitNetwork attack vector

Device crash via wrapped JPEG Content-Length

Published May 27, 2026 · Updated May 27, 2026

Heap buffer overflow in Tasmota through 15.3.0.3 allows remote attackers to crash a device via a crafted MJPEG stream. In fetch_jpg() in xdrv_10_scripter.ino, atoi() parses Content-Length into a uint16_t, so values above 65535 wrap and drive an undersized heap allocation. Exploitation requires the device to fetch from an attacker-controlled server through a Tasmota script or a man-in-the-middle position; the demonstrated consequence is a crash or reboot, while code execution remains unverified.

CVSS severity7.3
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in Tasmota through 15.3.0.3 allows remote attackers to crash a device via a crafted MJPEG stream. In fetch_jpg() in xdrv_10_scripter.ino, atoi() parses Content-Length into a uint16_t, so values above 65535 wrap and drive an undersized heap allocation. Exploitation requires the device to fetch from an attacker-controlled server through a Tasmota script or a man-in-the-middle position; the demonstrated consequence is a crash or reboot, while code execution remains unverified.

The record

CVE
CVE-2026-38427
Published
May 27, 2026
Updated
May 27, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-122, CAPEC-92, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CAPEC-92Forced Integer Overflow
T1499Endpoint Denial of Service

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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